Citric Acid Cycle: A series of oxidative reactions in the breakdown of acetyl units derived from GLUCOSE; FATTY ACIDS; or AMINO ACIDS by means of tricarboxylic acid intermediates. The end products are CARBON DIOXIDE, water, and energy in the form of phosphate bonds.Citric Acid: A key intermediate in metabolism. It is an acid compound found in citrus fruits. The salts of citric acid (citrates) can be used as anticoagulants due to their calcium chelating ability.CitratesMalatesIsocitrate Dehydrogenase: An enzyme of the oxidoreductase class that catalyzes the conversion of isocitrate and NAD+ to yield 2-ketoglutarate, carbon dioxide, and NADH. It occurs in cell mitochondria. The enzyme requires Mg2+, Mn2+; it is activated by ADP, citrate, and Ca2+, and inhibited by NADH, NADPH, and ATP. The reaction is the key rate-limiting step of the citric acid (tricarboxylic) cycle. (From Dorland, 27th ed) (The NADP+ enzyme is EC 1.1.1.42.) EC 1.1.1.41.Oxaloacetates: Derivatives of OXALOACETIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that include a 2-keto-1,4-carboxy aliphatic structure.Fumarate Hydratase: An enzyme that catalyzes the reversible hydration of fumaric acid to yield L-malic acid. It is one of the citric acid cycle enzymes. EC 4.2.1.2.Aconitate Hydratase: An enzyme that catalyzes the reversible hydration of cis-aconitate to yield citrate or isocitrate. It is one of the citric acid cycle enzymes. EC 4.2.1.3.Ketoglutaric Acids: A family of compounds containing an oxo group with the general structure of 1,5-pentanedioic acid. (From Lehninger, Principles of Biochemistry, 1982, p442)Pyruvic Acid: An intermediate compound in the metabolism of carbohydrates, proteins, and fats. In thiamine deficiency, its oxidation is retarded and it accumulates in the tissues, especially in nervous structures. (From Stedman, 26th ed)Ketoglutarate Dehydrogenase ComplexOxaloacetic Acid: A dicarboxylic acid ketone that is an important metabolic intermediate of the CITRIC ACID CYCLE. It can be converted to ASPARTIC ACID by ASPARTATE TRANSAMINASE.Malate Dehydrogenase: An enzyme that catalyzes the conversion of (S)-malate and NAD+ to oxaloacetate and NADH. EC 1.1.1.37.Citrate (si)-Synthase: Enzyme that catalyzes the first step of the tricarboxylic acid cycle (CITRIC ACID CYCLE). It catalyzes the reaction of oxaloacetate and acetyl CoA to form citrate and coenzyme A. This enzyme was formerly listed as EC 4.1.3.7.Acetyl Coenzyme A: Acetyl CoA participates in the biosynthesis of fatty acids and sterols, in the oxidation of fatty acids and in the metabolism of many amino acids. It also acts as a biological acetylating agent.Succinic Acid: A water-soluble, colorless crystal with an acid taste that is used as a chemical intermediate, in medicine, the manufacture of lacquers, and to make perfume esters. It is also used in foods as a sequestrant, buffer, and a neutralizing agent. (Hawley's Condensed Chemical Dictionary, 12th ed, p1099; McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1851)Carbon Isotopes: Stable carbon atoms that have the same atomic number as the element carbon, but differ in atomic weight. C-13 is a stable carbon isotope.PyruvatesSuccinate Dehydrogenase: A flavoprotein containing oxidoreductase that catalyzes the dehydrogenation of SUCCINATE to fumarate. In most eukaryotic organisms this enzyme is a component of mitochondrial electron transport complex II.Acetates: Derivatives of ACETIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxymethane structure.GlyoxylatesSuccinate-CoA Ligases: Enzymes that catalyze the first step leading to the oxidation of succinic acid by the reversible formation of succinyl-CoA from succinate and CoA with the concomitant cleavage of ATP to ADP (EC 6.2.1.5) or GTP to GDP (EC 6.2.1.4) and orthophosphate. Itaconate can act instead of succinate and ITP instead of GTP.EC 6.2.1.-.Fluoroacetates: Derivatives of acetic acid with one or more fluorines attached. They are almost odorless, difficult to detect chemically, and very stable. The acid itself, as well as the derivatives that are broken down in the body to the acid, are highly toxic substances, behaving as convulsant poisons with a delayed action. (From Miall's Dictionary of Chemistry, 5th ed)Cell Cycle: The complex series of phenomena, occurring between the end of one CELL DIVISION and the end of the next, by which cellular material is duplicated and then divided between two daughter cells. The cell cycle includes INTERPHASE, which includes G0 PHASE; G1 PHASE; S PHASE; and G2 PHASE, and CELL DIVISION PHASE.Fumarates: Compounds based on fumaric acid.Succinates: Derivatives of SUCCINIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain a 1,4-carboxy terminated aliphatic structure.Glycolysis: A metabolic process that converts GLUCOSE into two molecules of PYRUVIC ACID through a series of enzymatic reactions. Energy generated by this process is conserved in two molecules of ATP. Glycolysis is the universal catabolic pathway for glucose, free glucose, or glucose derived from complex CARBOHYDRATES, such as GLYCOGEN and STARCH.Glutamates: Derivatives of GLUTAMIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the 2-aminopentanedioic acid structure.Gluconeogenesis: Biosynthesis of GLUCOSE from nonhexose or non-carbohydrate precursors, such as LACTATE; PYRUVATE; ALANINE; and GLYCEROL.Ketone Bodies: The metabolic substances ACETONE; 3-HYDROXYBUTYRIC ACID; and acetoacetic acid (ACETOACETATES). They are produced in the liver and kidney during FATTY ACIDS oxidation and used as a source of energy by the heart, muscle and brain.Heptanoates: Salts and esters of the 7-carbon saturated monocarboxylic acid heptanoic acid.Malate Synthase: An important enzyme in the glyoxylic acid cycle which reversibly catalyzes the synthesis of L-malate from acetyl-CoA and glyoxylate. This enzyme was formerly listed as EC 4.1.3.2.Pyruvate Carboxylase: A biotin-dependent enzyme belonging to the ligase family that catalyzes the addition of CARBON DIOXIDE to pyruvate. It is occurs in both plants and animals. Deficiency of this enzyme causes severe psychomotor retardation and ACIDOSIS, LACTIC in infants. EC 6.4.1.1.Dicarboxylic Acid Transporters: A family of organic anion transporters that specifically transport DICARBOXYLIC ACIDS such as alpha-ketoglutaric acid across cellular membranes.Glucose: A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.Carbon Dioxide: A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.GlutaratesMitochondria: Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)Glutamine: A non-essential amino acid present abundantly throughout the body and is involved in many metabolic processes. It is synthesized from GLUTAMIC ACID and AMMONIA. It is the principal carrier of NITROGEN in the body and is an important energy source for many cells.Acetoacetates: Salts and derivatives of acetoacetic acid.Oxo-Acid-Lyases: Enzymes that catalyze the cleavage of a carbon-carbon bond of a 3-hydroxy acid. (Dorland, 28th ed) EC 4.1.3.Oxygen Consumption: The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)Keto AcidsEnergy Metabolism: The chemical reactions involved in the production and utilization of various forms of energy in cells.Acetic Acid: Product of the oxidation of ethanol and of the destructive distillation of wood. It is used locally, occasionally internally, as a counterirritant and also as a reagent. (Stedman, 26th ed)Magnetic Resonance Spectroscopy: Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).Oxidation-Reduction: A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).Lactic Acid: A normal intermediate in the fermentation (oxidation, metabolism) of sugar. The concentrated form is used internally to prevent gastrointestinal fermentation. (From Stedman, 26th ed)Hydro-Lyases: Enzymes that catalyze the breakage of a carbon-oxygen bond leading to unsaturated products via the removal of water. EC 4.2.1.Carbon: A nonmetallic element with atomic symbol C, atomic number 6, and atomic weight [12.0096; 12.0116]. It may occur as several different allotropes including DIAMOND; CHARCOAL; and GRAPHITE; and as SOOT from incompletely burned fuel.Coenzyme AGlutamic Acid: A non-essential amino acid naturally occurring in the L-form. Glutamic acid is the most common excitatory neurotransmitter in the CENTRAL NERVOUS SYSTEM.Aspartic Acid: One of the non-essential amino acids commonly occurring in the L-form. It is found in animals and plants, especially in sugar cane and sugar beets. It may be a neurotransmitter.Propionates: Derivatives of propionic acid. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxyethane structure.Perfusion: Treatment process involving the injection of fluid into an organ or tissue.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Aspergillus niger: An imperfect fungus causing smut or black mold of several fruits, vegetables, etc.Tricarboxylic Acids: Organic compounds that are acyclic and contain three acid groups. A member of this class is citric acid which is the first product formed by reaction of pyruvate and oxaloacetate. (From Lehninger, Principles of Biochemistry, 1982, p443)Kinetics: The rate dynamics in chemical or physical systems.Myocardium: The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.NAD: A coenzyme composed of ribosylnicotinamide 5'-diphosphate coupled to adenosine 5'-phosphate by pyrophosphate linkage. It is found widely in nature and is involved in numerous enzymatic reactions in which it serves as an electron carrier by being alternately oxidized (NAD+) and reduced (NADH). (Dorland, 27th ed)Menstrual Cycle: The period from onset of one menstrual bleeding (MENSTRUATION) to the next in an ovulating woman or female primate. The menstrual cycle is regulated by endocrine interactions of the HYPOTHALAMUS; the PITUITARY GLAND; the ovaries; and the genital tract. The menstrual cycle is divided by OVULATION into two phases. Based on the endocrine status of the OVARY, there is a FOLLICULAR PHASE and a LUTEAL PHASE. Based on the response in the ENDOMETRIUM, the menstrual cycle is divided into a proliferative and a secretory phase.Cough: A sudden, audible expulsion of air from the lungs through a partially closed glottis, preceded by inhalation. It is a protective response that serves to clear the trachea, bronchi, and/or lungs of irritants and secretions, or to prevent aspiration of foreign materials into the lungs.Taste: The ability to detect chemicals through gustatory receptors in the mouth, including those on the TONGUE; the PALATE; the PHARYNX; and the EPIGLOTTIS.Pyruvate Dehydrogenase Complex: A multienzyme complex responsible for the formation of ACETYL COENZYME A from pyruvate. The enzyme components are PYRUVATE DEHYDROGENASE (LIPOAMIDE); dihydrolipoamide acetyltransferase; and LIPOAMIDE DEHYDROGENASE. Pyruvate dehydrogenase complex is subject to three types of control: inhibited by acetyl-CoA and NADH; influenced by the energy state of the cell; and inhibited when a specific serine residue in the pyruvate decarboxylase is phosphorylated by ATP. PYRUVATE DEHYDROGENASE (LIPOAMIDE)-PHOSPHATASE catalyzes reactivation of the complex. (From Concise Encyclopedia Biochemistry and Molecular Biology, 3rd ed)Lactates: Salts or esters of LACTIC ACID containing the general formula CH3CHOHCOOR.Gas Chromatography-Mass Spectrometry: A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.Mitochondria, Heart: The mitochondria of the myocardium.Carboxylic Acids: Organic compounds containing the carboxy group (-COOH). This group of compounds includes amino acids and fatty acids. Carboxylic acids can be saturated, unsaturated, or aromatic.Culture Media: Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Oxidoreductases: The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9)Swine: Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).Mitochondria, Liver: Mitochondria in hepatocytes. As in all mitochondria, there are an outer membrane and an inner membrane, together creating two separate mitochondrial compartments: the internal matrix space and a much narrower intermembrane space. In the liver mitochondrion, an estimated 67% of the total mitochondrial proteins is located in the matrix. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p343-4)Antitussive Agents: Agents that suppress cough. They act centrally on the medullary cough center. EXPECTORANTS, also used in the treatment of cough, act locally.Fatty Acids: Organic, monobasic acids derived from hydrocarbons by the equivalent of oxidation of a methyl group to an alcohol, aldehyde, and then acid. Fatty acids are saturated and unsaturated (FATTY ACIDS, UNSATURATED). (Grant & Hackh's Chemical Dictionary, 5th ed)Rats, Sprague-Dawley: A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.Adenosine Triphosphate: An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.Bacillus subtilis: A species of gram-positive bacteria that is a common soil and water saprophyte.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Taste Threshold: The minimum concentration at which taste sensitivity to a particular substance or food can be perceived.Amino Acids: Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.Iron-Sulfur Proteins: A group of proteins possessing only the iron-sulfur complex as the prosthetic group. These proteins participate in all major pathways of electron transport: photosynthesis, respiration, hydroxylation and bacterial hydrogen and nitrogen fixation.Cell Cycle Proteins: Proteins that control the CELL DIVISION CYCLE. This family of proteins includes a wide variety of classes, including CYCLIN-DEPENDENT KINASES, mitogen-activated kinases, CYCLINS, and PHOSPHOPROTEIN PHOSPHATASES as well as their putative substrates such as chromatin-associated proteins, CYTOSKELETAL PROTEINS, and TRANSCRIPTION FACTORS.IsocitratesOsmeriformes: An order of fish including smelts, galaxiids, and salamanderfish.Aconitic AcidRoot Canal Irrigants: Chemicals used mainly to disinfect root canals after pulpectomy and before obturation. The major ones are camphorated monochlorophenol, EDTA, formocresol, hydrogen peroxide, metacresylacetate, and sodium hypochlorite. Root canal irrigants include also rinsing solutions of distilled water, sodium chloride, etc.Metacercariae: Encysted cercaria which house the intermediate stages of trematode parasites in tissues of an intermediate host.Quinine: An alkaloid derived from the bark of the cinchona tree. It is used as an antimalarial drug, and is the active ingredient in extracts of the cinchona that have been used for that purpose since before 1633. Quinine is also a mild antipyretic and analgesic and has been used in common cold preparations for that purpose. It was used commonly and as a bitter and flavoring agent, and is still useful for the treatment of babesiosis. Quinine is also useful in some muscular disorders, especially nocturnal leg cramps and myotonia congenita, because of its direct effects on muscle membrane and sodium channels. The mechanisms of its antimalarial effects are not well understood.Rats, Inbred Strains: Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.Gene Expression Regulation, Bacterial: Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.Smear Layer: Adherent debris produced when cutting the enamel or dentin in cavity preparation. It is about 1 micron thick and its composition reflects the underlying dentin, although different quantities and qualities of smear layer can be produced by the various instrumentation techniques. Its function is presumed to be protective, as it lowers dentin permeability. However, it masks the underlying dentin and interferes with attempts to bond dental material to the dentin.Acetobacter: A species of gram-negative bacteria of the family ACETOBACTERACEAE found in FLOWERS and FRUIT. Cells are ellipsoidal to rod-shaped and straight or slightly curved.Caproates: Derivatives of caproic acid. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain a carboxy terminated six carbon aliphatic structure.Estrous Cycle: The period of cyclic physiological and behavior changes in non-primate female mammals that exhibit ESTRUS. The estrous cycle generally consists of 4 or 5 distinct periods corresponding to the endocrine status (PROESTRUS; ESTRUS; METESTRUS; DIESTRUS; and ANESTRUS).Escherichia coli: A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.Heart: The hollow, muscular organ that maintains the circulation of the blood.Taste Perception: The process by which the nature and meaning of gustatory stimuli are recognized and interpreted by the brain. The four basic classes of taste perception are salty, sweet, bitter, and sour.Metabolome: The dynamic collection of metabolites which represent a cell's or organism's net metabolic response to current conditions.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Stars, Celestial: Large bodies consisting of self-luminous gas held together by their own gravity. (From McGraw Hill Dictionary of Scientific and Technical Terms, 6th ed)Sucrose: A nonreducing disaccharide composed of GLUCOSE and FRUCTOSE linked via their anomeric carbons. It is obtained commercially from SUGARCANE, sugar beet (BETA VULGARIS), and other plants and used extensively as a food and a sweetener.TartratesTongue: A muscular organ in the mouth that is covered with pink tissue called mucosa, tiny bumps called papillae, and thousands of taste buds. The tongue is anchored to the mouth and is vital for chewing, swallowing, and for speech.Pentose Phosphate Pathway: An oxidative decarboxylation process that converts GLUCOSE-6-PHOSPHATE to D-ribose-5-phosphate via 6-phosphogluconate. The pentose product is used in the biosynthesis of NUCLEIC ACIDS. The generated energy is stored in the form of NADPH. This pathway is prominent in tissues which are active in the synthesis of FATTY ACIDS and STEROIDS.RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.Hydrogen-Ion Concentration: The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)

Activities of glucose metabolic enzymes in human preantral follicles: in vitro modulation by follicle-stimulating hormone, luteinizing hormone, epidermal growth factor, insulin-like growth factor I, and transforming growth factor beta1. (1/1318)

Modulation of glucose metabolic capacity of human preantral follicles in vitro by gonadotropins and intraovarian growth factors was evaluated by monitoring the activities of phosphofructokinase (PFK) and pyruvate kinase (PK), two regulatory enzymes of the glycolytic pathway, and malate dehydrogenase (MDH), a key mitochondrial enzyme of the Krebs cycle. Preantral follicles in classes 1 and 2 from premenopausal women were cultured separately in vitro in the absence or presence of FSH, LH, epidermal growth factor (EGF), insulin-like growth factor (IGF-I), or transforming growth factor beta1 (TGFbeta1) for 24 h. Mitochondrial fraction was separated from the cytosolic fraction, and both fractions were used for enzyme assays. FSH and LH significantly stimulated PFK and PK activities in class 1 and 2 follicles; however, a 170-fold increase in MDH activity was noted for class 2 follicles that were exposed to FSH. Although both EGF and TGFbeta1 stimulated glycolytic and Krebs cycle enzymes for class 1 preantral follicles, TGFbeta1 consistently stimulated the activities of both glycolytic enzymes more than that of EGF. IGF-I induced PK and MDH activities in class 1 follicles but negatively influenced PFK activity for class 1 follicles. In general, only gonadotropins consistently stimulated both glycolytic and Krebs cycle enzyme activities several-fold in class 2 follicles. These results suggest that gonadotropins and ovarian growth factors differentially influence follicular energy-producing capacity from glucose. Moreover, gonadotropins may either directly influence glucose metabolism in class 2 preantral follicles or do so indirectly through factors other than the well-known intraovarian growth factors. Because growth factors modulate granulosa cell mitosis and functionality, their role on energy production may be related to specific cellular activities.  (+info)

Activities of citrate synthase, NAD+-linked and NADP+-linked isocitrate dehydrogenases, glutamate dehydrogenase, aspartate aminotransferase and alanine aminotransferase in nervous tissues from vertebrates and invertebrates. (2/1318)

1. The activities of citrate synthase and NAD+-linked and NADP+-linked isocitrate dehydrogenases were measured in nervous tissue from different animals in an attempt to provide more information about the citric acid cycle in this tissue. In higher animals the activities of citrate synthase are greater than the sum of activities of the isocitrate dehydrogenases, whereas they are similar in nervous tissues from the lower animals. This suggests that in higher animals the isocitrate dehydrogenase reaction is far-removed from equilibrium. If it is assumed that isocitrate dehydrogenase activities provide an indication of the maximum flux through the citric acid cycle, the maximum glycolytic capacity in nervous tissue is considerably greater than that of the cycle. This suggest that glycolysis can provide energy in excess of the aerobic capacity of the tissue. 2. The activities of glutamate dehydrogenase are high in most nervous tissues and the activities of aspartate aminotransferase are high in all nervous tissue investigated. However, the activities of alanine aminotransferase are low in all tissues except the ganglia of the waterbug and cockroach. In these insect tissues, anaerobic glycolysis may result in the formation of alanine rather than lactate.  (+info)

The importance of pyruvate availability to PDC activation and anaplerosis in human skeletal muscle. (3/1318)

No studies have singularly investigated the relationship between pyruvate availability, pyruvate dehydrogenase complex (PDC) activation, and anaplerosis in skeletal muscle. This is surprising given the functional importance attributed to these processes in normal and disease states. We investigated the effects of changing pyruvate availability with dichloroacetate (DCA), epinephrine, and pyruvate infusions on PDC activation and accumulation of acetyl groups and tricarboxylic acid (TCA) cycle intermediates (TCAI) in human muscle. DCA increased resting PDC activity sixfold (P < 0.05) but decreased the muscle TCAI pool (mmol/kg dry muscle) from 1.174 +/- 0.042 to 0.747 +/- 0.055 (P < 0.05). This was probably a result of pyruvate being diverted to acetyl-CoA and acetylcarnitine after near-maximal activation of PDC by DCA. Conversely, neither epinephrine nor pyruvate activated PDC. However, both increased the TCAI pool (1.128 +/- 0.076 to 1.614 +/- 0.188, P < 0.05 and 1.098 +/- 0.059 to 1.385 +/- 0.114, P < 0.05, respectively) by providing a readily available pool of pyruvate for anaplerosis. These data support the hypothesis that TCAI pool expansion is principally a reflection of increased muscle pyruvate availability and, together with our previous work (J. A. Timmons, S. M. Poucher, D. Constantin-Teodosiu, V. Worrall, I. A. Macdonald, and P. L. Greenhaff. J. Clin. Invest. 97: 879-883, 1996), indicate that TCA cycle expansion may be of little functional significance to TCA cycle flux. It would appear therefore that the primary effect of DCA on oxidative ATP provision is to provide a readily available pool of acetyl groups to the TCA cycle at the onset of exercise rather than increasing TCA cycle flux by expanding the TCAI pool.  (+info)

Low oxygen inhibits but complex high-glucose medium facilitates in vitro maturation of squirrel monkey oocyte-granulosa cell complexes. (4/1318)

PURPOSE: The objectives of these in vitro maturation studies in primate cumulus-oocyte complexes (COCs) were to evaluate the effect of a reduced-oxygen environment and to compare medium with a high-glucose concentration to medium with pyruvate but no glucose. METHODS: COCs were retrieved from squirrel monkeys stimulated with 1 mg of follicle-stimulating hormone (FSH) for 4-6 days. Experiment 1 examined maturation after 48 hr in 5% O2/5% CO2/90% N2 compared with 5% CO2/air. The medium was CMRL-1066 containing moderate glucose (5.5 mM) supplemented with 1 mM glutamine, 0.33 mM pyruvate, 0.075 IU/ml human FSH, 5 IU/ml human chorionic gonadotropin, 75 U penicillin G/ml, and 20% fetal bovine serum. Experiment 2 in 5% CO2/air, compared P-1 medium (pyruvate and lactate but no glucose) to Waymouth's medium (27.5 mM glucose), both with identical supplements. RESULTS: Only 3 (8%) of 37 COCs matured in 5% O2, while 39 (49%) of 80 matured in ambient O2. Fourteen (22%) of 64 complexes matured in P-1 medium, compared to 47 (49%) of 96 meiosis II oocytes in Waymouth's medium (P < 0.05). CONCLUSIONS: These are the first primate studies showing detrimental effects of reduced-oxygen culture on in vitro maturation. Additionally, maturation was enhanced with complex high-glucose medium suggesting that the predominant metabolism is aerobic glycolysis.  (+info)

A minimal mechanism for bacterial pattern formation. (5/1318)

Colonies of Escherichia coli or Salmonella typhimurium form geometrically complex patterns when exposed to, or feeding on, intermediates of the tricarboxylic acid (TCA) cycle. In response to the TCA cycle intermediate, the bacteria secrete aspartate, a potent chemo-attractant. As a result, the cells form high-density aggregates arranged in striking regular patterns. The simplest are temporary spots formed in a liquid medium by both E. coli and S. typhimurium. In semi-solid medium S. typhimurium forms concentric rings arising from a low-density bacterial lawn, which are either continuous or spotted, whereas E. coli forms complex patterns arising from a dense swarm ring, including interdigitated spots (also called sunflower spirals), radial spots, radial stripes and chevrons. We present a mathematical model that captures all three of the pattern-forming processes experimentally observed in both E. coli and S. typhimurium, using a minimum of assumptions.  (+info)

The tricarboxylic acid cycle of Helicobacter pylori. (6/1318)

The composition and properties of the tricarboxylic acid cycle of the microaerophilic human pathogen Helicobacter pylori were investigated in situ and in cell extracts using [1H]- and [13C]-NMR spectroscopy and spectrophotometry. NMR spectroscopy assays enabled highly specific measurements of some enzyme activities, previously not possible using spectrophotometry, in in situ studies with H. pylori, thus providing the first accurate picture of the complete tricarboxylic acid cycle of the bacterium. The presence, cellular location and kinetic parameters of citrate synthase, aconitase, isocitrate dehydrogenase, alpha-ketoglutarate oxidase, fumarate reductase, fumarase, malate dehydrogenase, and malate synthase activities in H. pylori are described. The absence of other enzyme activities of the cycle, including alpha-ketoglutarate dehydrogenase, succinyl-CoA synthetase, and succinate dehydrogenase also are shown. The H. pylori tricarboxylic acid cycle appears to be a noncyclic, branched pathway, characteristic of anaerobic metabolism, directed towards the production of succinate in the reductive dicarboxylic acid branch and alpha-ketoglutarate in the oxidative tricarboxylic acid branch. Both branches were metabolically linked by the presence of alpha-ketoglutarate oxidase activity. Under the growth conditions employed, H. pylori did not possess an operational glyoxylate bypass, owing to the absence of isocitrate lyase activity; nor a gamma-aminobutyrate shunt, owing to the absence of both gamma-aminobutyrate transaminase and succinic semialdehyde dehydrogenase activities. The catalytic and regulatory properties of the H. pylori tricarboxylic acid cycle enzymes are discussed by comparing their amino acid sequences with those of other, more extensively studied enzymes.  (+info)

Replenishment and depletion of citric acid cycle intermediates in skeletal muscle. Indication of pyruvate carboxylation. (7/1318)

The effects of various substrates on the concentrations of free amino acids, citric acid cycle intermediates and acylcarnitines were studies in perfused hindquarter of rat in presence of glucose and insulin in order to assess regulatory mechanisms of the level of citric acid cycle intermediates in skeletal muscle. 1. Acetate and acetoacetate effected a significant increase in the level of citrate cycle intermediates and accumulation of acetylcarnitine. These changes were accompanied by a reduction in the level of alanine. The concentration of AMP was significantly elevated. 2. Muscle mitochondria fixed 14CO2 in the presence of pyruvate. The products were identified as malate or citrate when whole and disintegrated mitochondria were used respectively. The fixation was greatly stimulated by acetylcarnitine. 3. Acetylcarnitine inhibited the production of pyruvate from malate by muscle mitochondria. 4. Perfusion with 2-oxoisocaproate and 2-oxoisovalerate promoted increases in the level of citric cycle intermediates, a drop in both alanine and glutamate, and accumulation of branched-chain acylcarnitines. 2-Oxoisocaproate also caused a reduction of alanine released from the muscle. 5. Perfusion with leucine and valine did not change the concentration of citric acid cycle intermediates, but elevated glutamate and still more the concentration of alanine. 6. It is concluded that citric cycle intermediate level in the perfused resting muscle is modified by a) conditions which change the concentration of acetyl-CoA and thereby modify the rate of pyruvate carboxylation and decarboxylation of malate via malic enzyme b) conditions which change the concentration of pyruvate cause changes in alanine and cycle intermediates in the same direction via transamination reactions c) conditions which change the concentrations of 2-oxoacids which are converted to cycle intermediates via oxidation.  (+info)

Microbial oxidation of methane and methanol: isolation of methane-utilizing bacteria and characterization of a facultative methane-utilizing isolate. (8/1318)

A methane-utilizing organism capable of growth both on methane and on more complex organic substrates as a sole source of carbon and energy, has been isolated and studied in detail. Suspensions of methane-grown cells of this organism oxidized C-1 compounds (methane, methanol, formaldehyde, formate); hydrocarbons (ethane, propane); primary alcohols (ethanol, propanol); primary aldehydes (acetaldehyde, propionaldehyde); alkenes (ethylene, propylene); dimethylether; and organic acids (acetate, malate, succinate, isocitrate). Suspensions of methanol-or succinate-grown cells did not oxidize methane, ethane, propane, ethylene, propylene, or dimethylether, suggesting that the enzymatic systems required for oxidation of these substrates are induced only during growth on methane. Extracts of methane-grown cells contained a particulate reduced nicotinamide adenine dinucleotide-dependent methane monooxygenase activity. Oxidation of methanol, formaldehyde, and primary alcohols was catalyzed by a phenazine methosulfate-linked, ammonium ion-requiring methanol dehydrogenase. Oxidation of primary aldehydes was catalyzed by a phenazine methosulfate-linked, ammonium ion-independent aldehyde dehydrogenase. Formate was oxidized by a nicotinamide adenine dinucleotide-specific formate dehydrogenase. Extracts of methane-grown, but not succinate-grown, cells contained the key enzymes of the serine pathway, hydroxypyruvate reductase and malate lyase, indicating that the enzymes of C-1 assimilation are induced only during growth on C-1 compounds. Glucose-6-phosphate dehydrogenase was induced during growth on glucose. Extracts of methane-grown cells contained low levels of enzymes of the tricarboxylic acid cycle, including alpha-keto glutarate dehydrogenase, relative to the levels found during growth on succinate.  (+info)

*Succinate dehydrogenase

In step 6 of the citric acid cycle, SQR catalyzes the oxidation of succinate to fumarate with the reduction of ubiquinone to ... It is the only enzyme that participates in both the citric acid cycle and the electron transport chain. Histochemical analysis ... Why a common TCA cycle intermediate would inhibit Complex II is not entirely understood, though it may exert a protective role ... Succinate-analogue inhibitors include the synthetic compound malonate as well as the TCA cycle intermediates, malate and ...

*Citric acid cycle

... of the citric acid cycle at Smith College Citric acid cycle variants at MetaCyc Pathways connected to the citric acid cycle at ... The citric acid cycle (CAC) - also known as the tricarboxylic acid (TCA) cycle or the Krebs cycle - is a series of chemical ... However, because of the role of the citric acid cycle in anabolism, they might not be lost, since many citric acid cycle ... Citric Acid Cycle. Boston: Academic Press. ISBN 0-12-181870-5. Krebs HA, Weitzman PD (1987). Krebs' citric acid cycle: half a ...

*Glycolysis

Fatty acid synthesis Cholesterol synthesis The citric acid cycle which in turn leads to: Amino acid synthesis Nucleotide ... The resulting acetyl-CoA enters the citric acid cycle (or Krebs Cycle), where the acetyl group of the acetyl-CoA is converted ... Metabolism portal Molecular and cellular biology portal Carbohydrate catabolism Citric acid cycle Cori cycle Fermentation ( ... beta-oxidation of fatty acids, and during the citric acid cycle). The NADH thus produced is primarily used to ultimately ...

*Adenosine diphosphate

The citric acid cycle, also known as the Krebs cycle or the TCA (tricarboxylic acid) cycle is an 8-step process that takes the ... "Citric Acid Cycle" (PDF). Takusagawa's Note. Archived from the original (PDF) on 24 March 2012. Retrieved 4 April 2013. " ... ADP cycling supplies the energy needed to do work in a biological system, the thermodynamic process of transferring energy from ... During the initial phases of glycolysis and the TCA cycle, cofactors such as NAD+ donate and accept electrons that aid in the ...

*Pyruvate dehydrogenase (lipoamide) beta

Voet DJ, Voet JG, Pratt CW (2010). "Chapter 17, Citric Acid Cycle". Principles of Biochemistry (4th ed.). Wiley. p. 550. ISBN ... The PDHB gene encodes a precursor protein that has 359 amino acid residues and a final mature protein that has 329 amino acids ... and provides the primary link between glycolysis and the tricarboxylic acid (TCA) cycle. The PDH complex is composed of ... In forming the entire PDH complex, the 289th beta residue, aspartic acid, interacts with the 276th residue of the E2 complex, a ...

*Pyruvate dehydrogenase (lipoamide) alpha 2

Voet DJ, Voet JG, Pratt CW (2010). "Chapter 17, Citric Acid Cycle". Principles of Biochemistry (4th ed.). Wiley. p. 550. ISBN ... Pyruvate dehydrogenase deficiency is characterized by the buildup of a chemical called lactic acid in the body and a variety of ... The most common feature is a potentially life-threatening buildup of lactic acid (lactic acidosis), which can cause nausea, ...

*Pyruvate dehydrogenase (lipoamide) alpha 1

Voet DJ, Voet JG, Pratt CW (2010). "Chapter 17, Citric Acid Cycle". Principles of Biochemistry (4th ed.). Wiley. p. 550. ISBN ... The PDHA1 subunit has been shown to be regulated by free fatty acids during bouts of exercise. The presence of free fatty acids ... The preliminary peptide encoded by this gene was 29 amino acids at the very start of the sequence that correspond to a typical ... Pyruvate dehydrogenase deficiency is characterized by the buildup of a chemical called lactic acid in the body and a variety of ...

*1981 in science

November 22 - Hans Krebs (b. 1900), German medical doctor and biochemist; discoverer of the citric acid cycle. December 6 - ...

*Citrate-CoA ligase

This enzyme participates in citric acid cycle. Lill U, Schreil A, Eggerer H (1982). "Isolation of enzymically active fragments ... This enzyme belongs to the family of ligases, specifically those forming carbon-sulfur bonds as acid-thiol ligases. The ...

*Pyruvate dehydrogenase (acetyl-transferring)

OCHOA S (1954). "Enzymic mechanisms in the citric acid cycle". Adv. Enzymol. Relat. Subj. Biochem. 15: 183-270. PMID 13158180. ... pyruvic acid dehydrogenase, and pyruvic dehydrogenase. This enzyme participates in 5 metabolic pathways: glycolysis / ...

*2-oxoglutarate synthase

This enzyme participates in the Citric acid cycle. Some forms catalyze the reverse reaction within the Reverse Krebs cycle, as ... Mai X, Adams MW (1996). "Characterization of a fourth type of 2-keto acid-oxidizing enzyme from a hyperthermophilic archaeon: 2 ... Schut GJ, Menon AL, Adams MW (2001). "2-keto acid oxidoreductases from Pyrococcus furiosus and Thermococcus litoralis". Methods ...

*Pyruvate dehydrogenase deficiency

Oral citrate is often used to treat acidosis.[citation needed] Citric acid cycle Reference, Genetics Home. "pyruvate ... Cells with a normal allele active can metabolize the lactic acid that is released by the PDH deficient cells. They cannot, ...

*Phenothiazine

3.0.CO;2-6. "Citric acid cycle biomimic on a carbon electrode". Biosensors and Bioelectronics. 24: 939-944. doi:10.1016/j.bios. ...

*Aconitase

Fluoroacetate, in the citric acid cycle,can innocently enter as fluorocitrate. However, aconitase cannot bind this substrate ... Citric acid Aconitic acid Isocitric acid Aconitase, displayed in the structures in the right margin of this page, has two ... doi:10.1016/S0076-6879(02)49317-2. ISBN 978-0-12-182252-1. Takusagawa F. "Chapter 16: Citric Acid Cycle" (PDF). Takusagawa's ... and thus the citric acid cycle is halted. The iron sulfur cluster is highly sensitive to oxidation by superoxide. Aconitase ...

*Methylococcaceae

Catabolism does not involve a complete citric acid cycle. Some species of the Methylococcaceae have formed with certain marine ... Methane is oxidized to give formaldehyde, which is fixed by a process called the RuMP cycle (Ribulose Monophosphate Cycle). ...

*Glutaminolysis

Due to the truncation of the citric acid cycle the amount of acetyl-CoA infiltrated in the citric acid cycle is low and acetyl- ... citric acid cycle, malate-aspartate shuttle Krebs, HA; Bellamy D (1960). "The interconversion of glutamic acid and aspartic ... In tumor cells the citric acid cycle is truncated due to an inhibition of the enzyme aconitase (EC 4.2.1.3) by high ... Glutaminolysis partially recruits reaction steps from the citric acid cycle and the malate-aspartate shuttle. The conversion of ...

*Oxalosuccinic acid

... is a substrate of the citric acid cycle. It is acted upon by isocitrate dehydrogenase. Salts and esters of ... Oxalosuccinic acid/oxalosuccinate is an unstable 6-carbon intermediate in the tricarboxylic acid cycle. It's an alpha-keto ...

*Nutrition

Szent-Györgyi concurrently elucidated much of the citric acid cycle. In the 1930s, William Cumming Rose identified essential ... Fatty acids such as conjugated linoleic acid, catalpic acid, eleostearic acid and punicic acid, in addition to providing energy ... As there is no protein or amino acid storage provision, amino acids must be present in the diet. Excess amino acids are ... Most fatty acids are non-essential, meaning the body can produce them as needed, generally from other fatty acids and always by ...

*Caloric restriction mimetic

Oxaloacetate is a metabolic intermediate of the citric acid cycle. In the short-lived roundworm Caenorhabditis elegans, ... Therefore, it has similar effects as CR.[citation needed] Lipoic Acid (α-Lipoic Acid, Alpha Lipoic Acid, or ALA) has failed to ... Lee CK, Pugh TD, Klopp RG, Edwards J, Allison DB, Weindruch R, Prolla TA (Apr 15, 2004). "The impact of alpha-lipoic acid, ... Merry BJ, Kirk AJ, Goyns MH (June 2008). "Dietary lipoic acid supplementation can mimic or block the effect of dietary ...

*Inborn errors of carbohydrate metabolism

... and through the citric acid cycle (CAC) (see below, c.f. bioenergetic systems). The liver can also create glucose ( ... the pyruvate not converted feeds the citric acid cycle (CAC); both via pyruvate dehydrogenase (PDC, with Acetyl-CoA as ... cells also use the enzyme acid alpha-glucosidase in lysosomes to degrade glycogen. An deficiency of an involved enzyme results ...

*Fluoroacetic acid

It inhibits the aconitase step of the citric acid cycle. Fluoroacetate occurs naturally in at least 40 plants in Australia, ... Difluoroacetic acid Trifluoroacetic acid Proudfoot, A. T.; Bradberry, S. M.; Vale, J. A. (2006). "Sodium fluoroacetate ... Fluoroacetic acid is a chemical compound with formula CH2FCOOH. The sodium salt, sodium fluoroacetate, is used as a pesticide. ... As early as 1904, colonists in Sierra Leone used extracts of Chailletia toxicaria, which also contains fluoroacetic acid or its ...

*Randle cycle

This mechanism replenishes the intermediates of the citric acid cycle. The impairment of glucose metabolism by fatty acid ... The Randle cycle, also known as the glucose fatty-acid cycle, is a metabolic process involving the competition of glucose and ... The glucose fatty acid cycle is also observed in the fed state after a high-fat meal or during exercise. This is when plasma ... The Randle cycle is a biochemical mechanism involving the competition between glucose and fatty acids for their oxidation and ...

*Diethyl succinate

... is also present in the citric acid cycle. The ester bond acts as a good electron donor due to resonance, and ... For diethyl succinate, the carboxylic acid involved is succinic acid, or butanedioic acid, which is a dicarboxyllic acid. The ... Diethyl succinate plays a key role in the Krebs cycle, which is a component of metabolism. Since it is low in molecular weight ... RCOOH + R'OH ↔ RCOOR' + water Fisher esterification is a common method of synthesis in which the carboxylic acid reacts with an ...

*Human nutrition

Szent-Györgyi concurrently elucidated much of the citric acid cycle. In the 1930s William Cumming Rose identified essential ... The omega-3 eicosapentaenoic acid (EPA), which can be made in the human body from the omega-3 essential fatty acid alpha- ... An appropriate balance of essential fatty acids - omega-3 and omega-6 fatty acids - seems also important for health, though ... Other essential nutrients not classed as vitamins include essential amino acids (see above), essential fatty acids (see above ...

*Adenosine triphosphate

... which is fully oxidized to carbon dioxide by the citric acid cycle (also known as the Krebs cycle). Every "turn" of the citric ... The citric acid cycle is regulated mainly by the availability of key substrates, particularly the ratio of NAD+ to NADH and the ... Although the citric acid cycle itself does not involve molecular oxygen, it is an obligately aerobic process because O2 is used ... In the absence of oxygen, the citric acid cycle ceases. The generation of ATP by the mitochondrion from cytosolic NADH relies ...

*Metabolism

... glycolysis and fed into the citric acid cycle. Although some more ATP is generated in the citric acid cycle, the most important ... He discovered the urea cycle and later, working with Hans Kornberg, the citric acid cycle and the glyoxylate cycle. Modern ... Amino acids also contribute to cellular energy metabolism by providing a carbon source for entry into the citric acid cycle ( ... For example, the set of carboxylic acids that are best known as the intermediates in the citric acid cycle are present in all ...

*Outline of cell biology

Pyruvate dehydrogenase - Citric acid cycle - Also known as the Krebs cycle, an important aerobic metabolic pathway. Electron ... Hans Adolf Krebs - Discovered the citric acid cycle in 1937. Konstantin Mereschkowski - Russian botanist who in 1905 described ... DNA - Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions used in the development and ... DNA helicase DNA polymerase DNA ligase RNA - Ribonucleic acid is a nucleic acid made from a long chain of nucleotide, in a cell ...
Citric acid cycle (tricarboxylic acid cycle, TCA cycle, Krebs cycle) is a series of chemical reactions used by all aerobic organisms to generate energy through the oxidation of acetate derived from carbohydrates, fats and proteins into carbon dioxide and chemical energy in the form of adenosine triphosphate (ATP). [Citric acid cycle. Wikipedia] |br|This biochemical diagram example shows metabolic pathways map of citric acid cycle reactions. |br|This sample was redesigned from the Wikimedia Commons file: TCA cycle.svg. [commons.wikimedia.org/wiki/File:TCA_cycle.svg] |br|This image is licensed under the Creative Commons Attribution 3.0 Unported license. [creativecommons.org/licenses/by/3.0/deed.en] |br|The metabolic pathway map example Citric acid cycle (TCA cycle) was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Biology solution from the Science and Education area of ConceptDraw Solution Park. Citric Acid Cycle
Definition of citric acid cycle in the Legal Dictionary - by Free online English dictionary and encyclopedia. What is citric acid cycle? Meaning of citric acid cycle as a legal term. What does citric acid cycle mean in law?
The glyxoylate shunt consists of two enzymes, isocitrate lyase and malate synthase. Its function is generally anaplerotic, meaning that it replenishes TCA cycle intermediates. Isocitrate (one intermediate) becomes succinate (one intermediate) plus glyoxylate. Glyoxylate plus an acetyl group from acetyl-CoA becomes malate, a second intermediate, for a gain of one. Acetyl groups, such as from fatty acid metabolism, by means of this pathway, can provide TCA cycle intermediates for use in amino acid biosynthesis and other biosynthetic pathways ...
Montalbo, R G. and Kabara, J J., "Tricarboxylic acid cycle intermediates in muscular dystrophic mice (strain 129)." (1974). Subject Strain Bibliography 1974. 1366 ...
THE CITRIC ACID CYCLE aka Krebs cycle or Tricarboxylic acid (TCA) cycle Overview of Citric Acid Cycle Feed to cycle is the acetyl group note that this is already partially oxidized In this cycle, we will
The citric acid cycle (CAC) is the central pathway of energy transfer for many organisms, and understanding the origin of this pathway may provide insight into the origins of metabolism. In order to assess the thermodynamics of this key pathway for microorganisms that inhabit a wide variety of environments, especially those found in high temperature environments, we have calculated the properties and parameters for the revised Helgeson-Kirkham-Flowers equation of state for the major components of the CAC. While a significant amount of data is not available for many of the constituents of this fundamental pathway, methods exist that allow estimation of these missing data.
Citric acid cycle Citric acid cycle (Krebs cycle, tricarboxylic acid cycle) is a series of reactions in mitochondria that bring about the catabolism of acetyl residues, liberating hydrogen equivalents,
The growth and survival of cancer cells is dependent on extracellular glutamine, which is frequently depleted in solid tumors, resulting in the induction of apoptosis. Glutamine has been suggested to maintain cancer cell viability by replenishing intermediates for the tricarboxylic acid (TCA) cycle and supporting de novo biosynthesis of nucleotides and nonessential amino acids. Zhang and colleagues sought to characterize the mechanism by which glutamine withdrawal induces apoptosis using a high-throughput RNAi-based screen to identify genes whose loss protected MYC-transformed cells from apoptosis following glutamine withdrawal. Intriguingly, depletion of the TCA cycle enzyme citrate synthase (CS) protected cancer cells from glutamine withdrawal-induced cell death. In the absence of glutamine, knockdown of CS resulted in diminished glycolytic flux through the TCA cycle and redirection of the TCA cycle intermediate oxaloacetate to the synthesis of the nonessential amino acids aspartate and ...
Kreb cycle is the second step in plant respiration. It occurs in the mitochondrial matrix. In honour of Krebs, cyclic chemical changes occurring in the matrix of the mitochondrion together are called Krebs cycle. First organic acid formed during Krebs cycle is citric acid. Hence Krebs cycle is also called citric acid cycle. It is also known as tricarboxylic acid (TCA) as citric acid. Read more ...
Koi, Goldfish & Pond Health Nitrite - By Product of Cycle Metabolism of Ammonia by Beneficial Nitrogen Reducing Bacteria in the Pond Brown Blood methemoglobinemia
To test this pathway, we traced the metabolic fate of [U-14C]Thr in mESCs with high-performance liquid chromatography (HPLC). 14C was incorporated into Gly and Glu, indicating that Thr was used to synthesize these amino acids (Fig. 2B). In contrast, MEFs incubated with [U-14C]Thr did not exhibit Thr catabolism (fig. S2A). We also traced the fate of [U-13C]Thr in mESCs with LC-MS/MS metabolomics (fig. S2, B to F, and table S1). mESCs used Thr to synthesize acetyl-CoA-derived tricarboxylic acid (TCA) cycle intermediates (Fig. 2, C and D). At steady state, [U-13C]Thr contributed ~20% of the citrate via acetyl-CoA, whereas [U-13C]glucose contributed ~35% via acetyl-CoA (+2 isotopomer). Thus, Thr contributes significantly to the acetyl-CoA pool in mESCs (Fig. 2D). [U-13C]Thr-derived Gly also donated its 13C-methyl group to ultimately generate 5-methyltetrahydrofolate (5mTHF) and SAM (+1 isotopomer), whereas [U-13C]Ser-derived Gly contributed little to the synthesis of these metabolites (Fig. 2, C and ...
Synonyms for citric acid cycles at Thesaurus.com with free online thesaurus, antonyms, and definitions. Dictionary and Word of the Day.
The model shows some of the prominent aspects of metabolism in proliferating cells, including glycolysis; lactate production; the use of TCA cycle intermediates as macromolecular precursors; and the biosynthesis of proteins, nucleotides, and lipids. The PI3K/Akt/mTOR pathway, HIF-1α, and Myc participate in various facets of this metabolic phenotype. The binding of a growth factor (GF) to its surface receptor brings about activation of PI3K and the serine/threonine kinases Akt and mTOR (top left). Constitutive activation of the pathway can occur in tumors due to mutation of the tumor suppressors PTEN, TSC1, and TSC2, or by other mechanisms (see text). Metabolic effects of the PI3K/Akt/mTOR pathway include enhanced uptake of glucose and essential amino acids and protein translation. The transcription factor HIF-1α (bottom) is involved in determining the manner in which cells utilize glucose carbon. Translation of HIF-1α is enhanced during growth-factor stimulation of the PI3K/Akt/mTOR pathway. ...
Citric acid cycle (tricarboxylic acid cycle, TCA cycle, Krebs cycle) is a series of chemical reactions used by all aerobic organisms to generate energy through the oxidation of acetate derived from carbohydrates, fats and proteins into carbon dioxide and chemical energy in the form of adenosine triphosphate (ATP). [Citric acid cycle. Wikipedia] |br|This biochemical diagram example shows metabolic pathways map of citric acid cycle reactions. |br|This sample was redesigned from the Wikimedia Commons file: TCA cycle.svg. [commons.wikimedia.org/wiki/File:TCA_cycle.svg] |br|This image is licensed under the Creative Commons Attribution 3.0 Unported license. [creativecommons.org/licenses/by/3.0/deed.en] |br|The metabolic pathway map example Citric acid cycle (TCA cycle) was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Biology solution from the Science and Education area of ConceptDraw Solution Park. Krebs Cycle Hd Image
In the fed state, most fatty acid-derived acylcarnitine species were present at similar levels in wild-type compared to the knockout mice. Notable exceptions included acetylcarnitine (C2) and beta-OH-butyrylcarnitine (C4OH, a strong marker of beta-oxidation and ketone metabolism), both of which were markedly decreased in plasma, liver, and skeletal muscle of PPARalpha -/- mice regardless of feeding status. Succinylcarnitine (C4DC), which arises from the TCA cycle intermediate succinyl-CoA, was reduced in plasma and liver of PPARalpha -/-mice, independent of condition. Skeletal muscle concentrations of this metabolite were also low in PPARalpha -/- compared to wild-type mice, but only in the fasted state ...
In the citric acid or tricarboxylic acid (TCA) cycle, the acetyl group of acetyl CoA (derived primarily from oxidative decarboxylation of pyruvate, beta-oxidation of long-chain fatty acids, and catabolism of ketone bodies and several amino acids) can be completely oxidized to CO2 in reactions that also yield one high-energy phosphate bond (as GTP or ATP) and four reducing equivalents (three NADH + H+, and one FADH2). The NADH and FADH2 are then oxidized by the electron transport chain to yield nine more high-energy phosphate bonds (as ATP). All reactions of the citric acid cycle take place in the mitochondrion.. Eight canonical reactions mediate the synthesis of citrate from acetyl-CoA and oxaloacetate and the metabolism of citrate to re-form oxaloacetate. Six additional reactions are included here. Three reversible reactions, the interconversions of citrate and isocitrate, of fumarate and malate, and of malate and oxaloacetate are annotated in both their canonical (forward) and reverse ...
To identify distinct biological pathways of glucose metabolism, we conducted a systematic evaluation of biochemical changes after an oral glucose tolerance test (OGTT) in a community-based population. Metabolic profiling was performed on 377 nondiabetic Framingham Offspring cohort participants (mean age 57 years, 42% women, BMI 30 kg/m2) before and after OGTT. Changes in metabolite levels were evaluated with paired Student t tests, cluster-based analyses, and multivariable linear regression to examine differences associated with insulin resistance. Of 110 metabolites tested, 91 significantly changed with OGTT (P ≤ 0.0005 for all). Amino acids, β-hydroxybutyrate, and tricarboxylic acid cycle intermediates decreased after OGTT, and glycolysis products increased, consistent with physiological insulin actions. Other pathways affected by OGTT included decreases in serotonin derivatives, urea cycle metabolites, and B vitamins. We also observed an increase in conjugated, and a decrease in ...
Krebs cycle animation and Citric acid cycle : Central metabolic cycle and its Significance Citric acid cycle is also called Krebs Cycle and Tricarboxylic acid cycle. The citric acid cycle is a aerobic universal Acetyl~coA catabolic cycle. It is a central metabolic cycle. The cycle was first elucidated by scientist "Sir Hans Adolf Krebs" (LT, […] ...
Solution for question: Distinguish Between Glycolysis and Citric Acid Cycle concept: Glycolysis. For the courses CBSE (Arts), CBSE (Commerce), CBSE (Science)
The Citric Acid Cycle is a series of enzyme catalyzed reactions which are critical in cellular respiration. In this cycle, Acetyl-CoA, a byproduct of glycolysis, along with various cofactors, are broken down into carbon dioxide, water, and energy in the form of GTP and NADH. ...
Free practice questions for High School Biology - Understanding the Citric Acid Cycle. Includes full solutions and score reporting.
Welcome back to my Coursera class, Biochemical Principles of Energy Metabolism. This is final session for week three, final session. Its about Oxidative Phosphorylation. Im just showing you the same slide repeatedly. Step number one of glucose degradation is glycolysis, C6 glucose phosphorylated. Its like energy and investment period and then, the glucose molecules will be split into C3 compound. We extract a little bit of ATP molecules and then pyruvic acid getting into the mitochondrial matrix. Inside of mitochondria matrix, there is citric acid cycle. Throughout this citric acid cycle, the carbon backbones will be fully oxidized and CO2 will be released and we can extract a lot of reduced electron carriers, throughout those oxidation, NAD, reduced NADH or FADH2. This is step number two. So far, in terms of number of ATP molecules, we cannot say glycolysis citric acid cycle are highly efficient energy-generating processes because during the glycolysis, four ATP molecules are produced. In ...
Since its formalization by Hans Krebs, the TCA cycle has proved to be a major turntable of the cell metabolism (33). The conversion of reducing power provided by the carboxylic acids into the respiratory chain-usable reduced coenzymes NADH and FADH2 constitutes a main function of the TCA. However, a number of cells, including mammalian cells, can survive the nonutilization of these cofactors by the respirator chain [rho zero cells devoid of respiratory chain due to the lack of mitochondrial DNA (mtDNA)] (31). The TCA also ensures a central role in an endless series of metabolic paths in particular, thanks to transamination reactions (24). Several major anaplerotic pathways require the TCA cycle-catalyzed breakdown of acetyl coenzyme A (acetyl-CoA) and the multistep interconversion of carbon skeletons delineated by Krebs (60). Finally, TCA cycle should also be considered as a water-splitting process generating oxygen for acetyl-CoA oxidation (64). Two reactions of the TCA cycle consume one H2O ...
In the mitochondrion, pyruvate is oxidized by the pyruvate dehydrogenase complex to acetyl CoA, which is fully oxidized to carbon dioxide by the citric acid cycle (also known as the Krebs Cycle). Every "turn" of the citric acid cycle produces two molecules of carbon dioxide, one molecule of the ATP equivalent guanosine triphosphate (GTP) through substrate-level phosphorylation catalyzed by succinyl CoA synthetase, three molecules of the reduced coenzyme NADH, and one molecule of the reduced coenzyme FADH2. Both of these latter molecules are recycled to their oxidized states (NAD+ and FAD, respectively) via the electron transport chain, which generates additional ATP by oxidative phosphorylation. The oxidation of an NADH molecule results in the synthesis of about 3 ATP molecules, and the oxidation of one FADH2 yields about 2 ATP molecules.[14] The majority of cellular ATP is generated by this process. Although the citric acid cycle itself does not involve molecular oxygen, it is an obligately ...
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Most animals are able to generate energy using either aerobic or anaerobic metabolic pathways, with glycolytic anaerobic respiration generating approximately 2 ATP molecules and aerobic respiration (citric acid cycle+oxidative phosphorylation) approximately 36.. Although the citric acid cycle does not directly rely on free oxygen, it does not take place under anaerobic conditions. As there is no free oxygen to act as the final electron acceptor, the intermediates all along the oxidative phosphorylation chain remain in a reduced state. As a result, the chain stops functioning, and the build up of the end products means (via Le Chateliers Principle) that the citric acid cycle, too, halts. However, glycolysis can still occur, leading to a build up of pyruvate and a small amount of ATP (two to three molecules).. So much for the basic biochemistry, the broad outline of which is extremely well known. What is less well known, however, is the presence of a variety of anaerobic respiratory pathways in ...
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Glucose catabolism via cellular respiration can be grouped into three major metabolic stages, these are (1) glycolysis, (2) the Krebs cycle also known as the citric acid cycle, and the tricarboxylic acid cycle (TCA cycle), and (3) the electron transport chain and oxidative phosphorylation. In eukaryotic cells, glycolysis occurs in the cytoplasm of the cell. The Krebs cycle occurs in the mitochondrial matrix while the reactions of the electron transport chain and oxidative phosphorylation occur on the cristae of the mitochondrion. These pathways rely on oxidation reduction reactions in which electrons are enzymatically removed (oxidation) from glucose and transferred (reduction) to electron acceptor molecules such as nicotinamide adenine dinucleotide (NAD+). Upon receiving electrons, NAD+ is reduced to NADH which functions as an electron carrier that supplies electrons to an electron transport chain in mitochondria that will ultimately power ATP synthesis in the reactions known as oxidative ...
In this cycle,citric acid is first consumed and then regenerated in a sequence of reactions. All aerobic organisms use this cycle to generate energy.
2CGO: Structural and Mechanistic Studies on the Inhibition of the Hypoxia-Inducible Transcription Factor Hydroxylases by Tricarboxylic Acid Cycle Intermediates.
The protein encoded by this gene is a Krebs tricarboxylic acid cycle enzyme that catalyzes the synthesis of citrate from oxaloacetate and acetyl coenzyme A. The enzyme is found in nearly all cells capable of oxidative metablism. This protein is nuclear encoded and transported into the mitochondrial matrix, where the mature form is found. [provided by RefSeq, Jul 2008 ...
Secondly, the 39ATPs are calculated from the degradtion of glucose during glycolysis during one complete cycle going through all the steps to the breakdown to pyruvate and then through the citric acid cycle. Depending on several factors in the citric acid cycle the amount can come down to 36, 38 or 39 ATPs. This might seem confusing but it all depends on whether endproducts are used in other cycles as well, if theyre used for anabolism the final yield will of course be less since this consumes ATP. Just remember that breakdown of glucose through oxidative phosphoryylation yields about 36-39 ATPs, much less than just breaking down glucose to lactic acid ...
This requires not only cyymbalta of the activity of the glycolytic and citric acid cycle enzymes, but also adequate oxygen and glucose delivery. 89266в270.
The irreducibly complex biochemical systems that I have discussed in this book did not have to be produced recently. It is entirely possible, based simply on an examination of the systems themselves, that they were designed billions of years ago and that they have been passed down to the present by the normal processes of cellular reproduction. Perhaps a speculative scenario will illustrate the point. Suppose that nearly four billion years ago the designer made the first cell, already containing all of the irreducibly complex biochemical systems discussed here and many others. (One can postulate that the designs for systems that were to be used later, such as blood clotting, were present but not turned on. In present-day organisms plenty of genes are turned off for a while, sometimes for generations, to be turned on at a later time.) Additionally. suppose the designer placed into the cell some other systems for which we cannot adduce enough evidence to conclude design. The cell containing the ...
Free categorised medical mnemonics and study material to help students of health related professions remember their topics better.
Oxidative stress involves damage to cellular structures caused by free radicals, or toxic oxygen molecules. Free radicals are normal byproducts of cellular activities, and the bodys natural defenses normally hold them in check. However, these defenses appear to decline with age, and oxidative stress may contribute to cell damage in Alzheimers disease. Many investigators are studying the precise biological mechanisms behind oxidative stress and its effects on the Alzheimer brain. In preliminary research, Qingli Shi, Ph.D., and colleagues have found that Alzheimer-related oxidative stress alters the transcription, or "activation," of certain enzymes from the genes that encode them. These enzymes exist in mitochondria, cellular structures that use oxygen and nutrients to produce energy for a cell. The enzymes are involved in a process called the tricarboxylic acid (TCA) cycle. Altered TCA cycle enzymes may inhibit the TCA cycle process and reduce the brains ability to break down harmful ...
Since it is well known that ATP is the energy currency that is used for nearly every task in the human body and other organisms, it may seem surprising that so little ATP is produced directly by the TCA cycle. But the TCA cycle as shown here represents the process taking place in the matrix of the mitochondria using the reactions with NAD+ and FAD which carry high energy electrons to the electron transport systems in the inner mitochondrial membrane. The reactions there are responsible for the production of most of the ATP yield by chemiosmosis.. ...
Introduction to the metabolism - Catabolism. Anabolism. General aspects of metabolism regulation. Carbohydrates metabolism: digestion and absorption of carbohydrates. Glyolysis. Synthesis and catabolism of glycogen. The pentose pathway. The Krebs citric acid cycle. Gluconeogenesis. Lipid metabolism: digestion and absorption of fat. Fatty acids b-oxidation. Synthesis and oxidation of ketone bodies. Biosynthesis of fatty acids. Structure and function of cholesterol. Amino acid metabolism: digestion of proteins and absorption of amino acids. Essential and non-essential aminoacids. Main reactions of amino acids: deamination and transamination. Fate of the amino group and ammonia. The urea cycle. Decarboxylation ...
This is the intro and conclusion to the paper I just handed in. I cut out all the middle /good stuff because if you arent into cell metabolism, it is probably not of interest.IntroductionHyperglycemia enhances the uptake of glucose into the liver, which thus increases the metabolic pathways of glycolysis, the citric acid cycle, and…
Developed as part of Rafaels proprietary Altered Energy Metabolism Directed (AEMD) drug platform, CPI-613 was discovered at Stony Brook University. CPI-613 is designed to target the mitochondrial tricarboxylic acid (TCA) cycle, an indispensable process essential to tumor cell multiplication and survival, selectively in cancer cells.. CPI-613s attack on the TCA cycle also substantially increases the sensitivity of cancer cells to a diverse range of chemotherapeutic agents. This synergy allows for combinations of CPI-613 with lower doses of these generally toxic drugs to be highly effective with lower patient side effects. Combinations with CPI-613 represent a diverse range of potential opportunities to substantially improve patient benefit in many different cancers.. ...
The major difference between anaerobic and aerobic conditions is the requirement of oxygen. Anaerobic processes do not require oxygen while aerobic...
The aims of this study were twofold: (i) to determine quantitatively the contribution of glutamate/glutamine cycling to total astrocyte/neuron substrate trafficking for the replenishment of neurotransmitter glutamate; and (ii) to determine the relative contributions of anaplerotic flux and glutamate/glutamine cycling to total glutamine synthesis. In this work in vivo and in vitro (13)C NMR spectroscopy were used, with a [2-(13)C]glucose or [5-(13)C]glucose infusion, to determine the rates of glutamate/glutamine cycling, de novo glutamine synthesis via anaplerosis, and the neuronal and astrocytic tricarboxylic acid cycles in the rat cerebral cortex. The rate of glutamate/glutamine cycling measured in this study is compared with that determined from re-analysis of (13)C NMR data acquired during a [1-(13)C]glucose infusion. The excellent agreement between these rates supports the hypothesis that glutamate/glutamine cycling is a major metabolic flux ( approximately 0.20 micromol/min/g) in the cerebral
1. The metabolism of L-alanine was studied in isolated guinea-pig kidney-cortex tubules. 2. In contrast with previous conclusions of Krebs [(1935) Biochem. J. 29, 1951-1969], glutamine was found to be the main carbon and nitrogenous product of the metabolism of alanine (at 1 and 5 mM). Glutamate and ammonia were only minor products. 3. At neither concentration of alanine was there accumulation of glucose, glycogen, pyruvate, lactate, aspartate or tricarboxylic acid-cycle intermediates. 4. Carbon-balance calculations and the release of 14CO2 from [U-14C]alanine indicate that oxidation of the alanine carbon skeleton occurred at both substrate concentrations. 5. A pathway involving alanine aminotransferase, glutamate dehydrogenase, glutamine synthetase, pyruvate dehydrogenase, pyruvate carboxylase and enzymes of the tricarboxylic acid cycle is proposed for the conversion of alanine into glutamine. 6. Strong evidence for this pathway was obtained by: (i) suppressing alanine removal by ...
Pancreatic beta cells integrate signals from several metabolites and hormones to control the secretion of insulin. In general, glucose triggers insulin secretion while other factors can amplify or inhibit the amount of insulin secreted in response to glucose. Factors which increase insulin secretion include the incretin hormones Glucose-dependent insulinotropic polypeptide (GIP and glucagon-like peptide-1 (GLP-1), acetylcholine, and fatty acids. Factors which inhibit insulin secretion include adrenaline and noradrenaline.. Increased blood glucose levels from dietary carbohydrate play a dominant role in insulin release from the beta cells of the pancreas. Glucose catabolism in the beta cell is the transducer that links increased glucose levels to insulin release. Glucose uptake and glycolysis generate cytosolic pyruvate; pyruvate is transported to mitochondria and converted both to oxaloacetate which increases levels of TCA cycle intermediates, and to acetyl-CoA which is oxidized to CO2 via the ...
Our results indicate that autopolyploidization was accompanied by negative effects, leading to overall disadvantages in plant fitness. These disadvantages included impaired pollen and seed viability, reduced seed germination, smaller fruit size, and lower tetrad number. As expected for such significant morphological and cytological modifications, there were also metabolic changes in the fruits and seeds following genome doubling. In both these tissues, the concentrations of sugars decreased, together with significant increases in the relative abundance of amino acids, TCA cycle intermediates, and organic acids. Targeted analysis of secondary metabolites in the fruit pulp revealed increased abundance of several flavonoids together with decreases in the concentrations of the major betacyanins.. Since plant cell size is correlated with genome size, it may be said that polyploidization is associated with an overall increase in the sizes of cells, tissues and organs [44]. Alterations in cellular ...
This chapter talks about fatty acid biosynthesis, linked to the citric acid cycle (CAC) through the utilization of acetyl-coenzyme A (CoA) as its starting point. The oxidative decarboxylation of pyruvate is an important reaction in archaea, bacteria, and eukaryotes alike, generating acetyl-CoA necessary for CAC reactions, fatty acid biosynthesis, and many other reactions requiring acyl-CoA. Citrate synthase catalyzes the first step in the oxidative branch of the CAC in which acetyl-CoA and oxaloacetate are condensed to generate citrate and CoA. Aconitase activity has been detected in the cytosolic fraction of Helicobacter pylori cells both by nuclear magnetic resonance (NMR) and spectrophotometric assays. In Escherichia coli isocitrate dehydrogenase acts as a critical branch point between the CAC reactions and the glyoxylate bypass during growth on C2 compounds like acetate. The study of the lipid and fatty acid profiles of eight Helicobacter species has revealed some characteristic features of the
The citric acid cycle (also named tricarboxylic acid (TCA) cycle or the Krebs cycle), is a collection of 9 enzyme-catalyzed chemical reactions that occur in all living cells undergoing aerobic respiration. The citric acid cycle itself was officially identified in 1937 by Hans Adolf Krebs, who received the Nobel Prize for this discovery in 1953. In eukaryotes, the citric acid cycle occurs in the mitochondria. In prokaryotes, the TCA cycle occurs in the cytoplasm. The TCA cycle starts with acetyl-CoA, which is the “fuel†for the entire cycle. This important molecule comes from the breakdown of glycogen (a stored form of glucose), fats, and many amino acids. At beginning, acetyl-CoA first transfers its 2-carbon acetyl group to the 4-carbon acceptor compound called oxaloacetate to form the 6-carbon compound (citrate) for which the cycle is named. The resulting citrate will have numbers of chemical transformations, whereby it loses one carboxyl group (leading to the 5-carbon compound called ...
1. The contents of some intermediates of glycolysis, the citric acid cycle and adenine nucleotides have been measured in the freeze-clamped locust flight muscle at rest and after 10s and 3min flight. The contents of glucose 6-phosphate, pyruvate, alanine and especially fructose bisphosphate and triose phosphates increased markedly upon flight. The content of acetyl-CoA is decreased after 3min flight whereas that of acetylcarnitine is decreased markedly after 10s flight, but returns towards the resting value after 3min flight. The content of citrate is markedly decreased after both 10s and 3min flight, whereas that of isocitrate is changed very little after 10s and is increased by 50% after 3min. The content of oxaloacetate is very low in insect flight muscle and hence it was measured by a sensitive radiochemical assay. The content of oxaloacetate increased about 2-fold after 3min flight. A similar change was observed in the content of malate. The content of ATP decreased about 15%, whereas those ...
As I said above the Krebs cycle was discovered by Hans Adolf Krebs in the year of 1937. The Krebs cycle occurs in an aerobic organism that is part of the metabolic pathway where it converts carbohydrates into water and carbon dioxide for usable energy in cellular respiration. The Krebs cycle starts with a glucose molecule and that glucose molecule is broken up due to the process of glycolysis into two pyruvates or pyruvic acids. Glyciolysis occurs in the cytoplasm. Remember, the Krebs cycle must go around two times to create one PGAL or G3P (glyceroldeyhde 3 phosphate). The next step of the Krebs cycle is the pyruvate joins with CoA, or coenzyme A, and forms a two carbon molecule called an acetyl group. After this acetyl group is formed, it joins with a four carbon molecule called oxaloacetic acid forming a six carbon molecule called citric acid. This is why the Krebs cycle is also referenced as the citric acid cycle. Throughout theKrebs cycle carbon dioxide molecules are released. For example, ...
Overview: The Citric Acid Cycle Review Activity is a multimedia approach for teaching an appreciation of cyclical events in cellular respiration. It takes advantage of written and audio instruction and guidance to direct students in a hands on round of the Citric Acid Cycle. By completing this activity, students will learn about the cyclical nature of the making ATP, and they will develop curiosities about some of the interesting but more complex biochemical transformations that occur within the Citric Acid Cycle. This activity ends with a take home writing assignment to synthesize the students ...
The citrate cycle (TCA cycle, Krebs cycle) is an important aerobic pathway for the final steps of the oxidation of carbohydrates and fatty acids. The cycle starts with acetyl-CoA, the activated form of acetate, derived from glycolysis and pyruvate oxidation for carbohydrates and from beta oxidation of fatty acids. The two-carbon acetyl group in acetyl-CoA is transferred to the four-carbon compound of oxaloacetate to form the six-carbon compound of citrate. In a series of reactions two carbons in citrate are oxidized to CO2 and the reaction pathway supplies NADH for use in the oxidative phosphorylation and other metabolic processes. The pathway also supplies important precursor metabolites including 2-oxoglutarate. At the end of the cycle the remaining four-carbon part is transformed back to oxaloacetate. According to the genome sequence data, many organisms seem to lack genes for the full cycle [MD:M00009], but contain genes for specific segments [MD:M00010 M00011 ...
The citrate cycle (TCA cycle, Krebs cycle) is an important aerobic pathway for the final steps of the oxidation of carbohydrates and fatty acids. The cycle starts with acetyl-CoA, the activated form of acetate, derived from glycolysis and pyruvate oxidation for carbohydrates and from beta oxidation of fatty acids. The two-carbon acetyl group in acetyl-CoA is transferred to the four-carbon compound of oxaloacetate to form the six-carbon compound of citrate. In a series of reactions two carbons in citrate are oxidized to CO2 and the reaction pathway supplies NADH for use in the oxidative phosphorylation and other metabolic processes. The pathway also supplies important precursor metabolites including 2-oxoglutarate. At the end of the cycle the remaining four-carbon part is transformed back to oxaloacetate. According to the genome sequence data, many organisms seem to lack genes for the full cycle [MD:M00009], but contain genes for specific segments [MD:M00010 M00011 ...
The citrate cycle (TCA cycle, Krebs cycle) is an important aerobic pathway for the final steps of the oxidation of carbohydrates and fatty acids. The cycle starts with acetyl-CoA, the activated form of acetate, derived from glycolysis and pyruvate oxidation for carbohydrates and from beta oxidation of fatty acids. The two-carbon acetyl group in acetyl-CoA is transferred to the four-carbon compound of oxaloacetate to form the six-carbon compound of citrate. In a series of reactions two carbons in citrate are oxidized to CO2 and the reaction pathway supplies NADH for use in the oxidative phosphorylation and other metabolic processes. The pathway also supplies important precursor metabolites including 2-oxoglutarate. At the end of the cycle the remaining four-carbon part is transformed back to oxaloacetate. According to the genome sequence data, many organisms seem to lack genes for the full cycle [MD:M00009], but contain genes for specific segments [MD:M00010 M00011 ...
The citrate cycle (TCA cycle, Krebs cycle) is an important aerobic pathway for the final steps of the oxidation of carbohydrates and fatty acids. The cycle starts with acetyl-CoA, the activated form of acetate, derived from glycolysis and pyruvate oxidation for carbohydrates and from beta oxidation of fatty acids. The two-carbon acetyl group in acetyl-CoA is transferred to the four-carbon compound of oxaloacetate to form the six-carbon compound of citrate. In a series of reactions two carbons in citrate are oxidized to CO2 and the reaction pathway supplies NADH for use in the oxidative phosphorylation and other metabolic processes. The pathway also supplies important precursor metabolites including 2-oxoglutarate. At the end of the cycle the remaining four-carbon part is transformed back to oxaloacetate. According to the genome sequence data, many organisms seem to lack genes for the full cycle [MD:M00009], but contain genes for specific segments [MD:M00010 M00011 ...
SYNOPSES OF COURSES. MBM 1101: Anatomy I. General Introduction to Gross Anatomy, Microscopic Anatomy (Histology) and Developmental Anatomy (Embryology). Lower Limb and Upper Limb anatomy gross, Musculoskeletal Histology and Embryology. MBM 1102: Biochemistry I - Catabolism and Genetics. Biomolecules: Water as solvent, introduction to macromolecular chemistry , structure and function. Enzyme activity and kinetics. Cell Biology and Metabolic Energy: Introduction to major cell structures and processes. The cell membrane, Energy concepts, glycolysis, the citric acid cycle and ATP.. Food and Digestion: Macronutrients and micronutrients. Digestive enzymes and absorption processes in the GIT. Lipid uptake and transport. Diarrhea.. Nutrient Metabolism: The Embden -Meyerhof pathway to citric acid cycle. Anaerobic metabolism, the Cori cycle. Fatty acid oxidation and the ketone bodies. Amino acids and the citric acid cycle. The urea cycle.. Human Genetics: Introduction to genetic concepts, genome projects, ...
3. The two major sets of reactions involved in photosynthesis are A. Calvin cycle reactions and citric acid cycles. B. glycolysis and the citric acid cycle. C. light reactions and the electron transport chain. D. light reactions and Calvin cycle reactions.
When the levels of ammonia in the brain are elevated, usually as a result of increased ammonia in the blood, the supply of glutamic acid (GLU) available from the the blood may be insufficient to form the additional amounts of glutamine (GLN) required to detoxify the ammonia in the brain. Under these circumstances glutamic acid is synthesized in the brain by amination of the ketoglutaric acid (KG) produced in the citric acid cycle within the brain itself. However, continuous utilization of ketoglutaric acid for this purpose would rapidly deplete the citric acid cycle of its intermediates unless a method of replenishing the cycle were available. Depletion is accomplished by CO2-fixation, involving pyruvate to form oxaloacetic acid (OA), which enters to the citric acid cycle and proceeds to the formation of ketoglutarate (KG). The reaction in brain is precisely analogous to that which occurs in the liver. ...
Citric acid crystals. Polarized light micrograph of a section through crystals of citric acid (tricarboxylic acid). Citric acid can be obtained from natural products such as the juices of citric fruits e.g.. lemons. It is also obtained by fermentation of glucose (citric acid cycle) and by synthesis. Magnification: x200 when printed at 10 centimetres tall. - Stock Image C026/2620
What is the difference between Krebs Cycle and Glycolysis? Krebs cycle (citric acid cycle / TCA cycle) occurs inside mitochondria of eukaryotes. Glycolysis
It is started by an enzymatic aldol addition reaction of acetyl CoA to oxaloacetate (1) forming citrate (2), which is then isomerized by a dehydration-hydration sequence to yield (2R,3S)-isocitrate (3).. Further enzymatic oxidation and decarboxylation gives 2- ketoglutarate (4), which, after another enzymatic decarboxylation and oxidation is, transformed into succinyl-CoA (5). The hydrolysis of this metabolite to succinate (6) is coupled to the phosphorylation of GDP to GTP.. Enzymatic desaturation by FAD-dependent succinate dehydrogenase yields fumarate (7), which, after stereospecific hydration catalyzed by fumarase is, transformed to L-malate (8).. The last step of NAD-coupled oxidation of L-malate (8) to oxaloacetate (1) is catalyzed by malate dehydrogenase and closes the cycle.. back to top ...
Chemicals - Water Treatment China, 2 Phosphonobutane 1 4 Tricarboxylic Acid Sodium Salt Pbtca Na4, 2-Phosphonobutane -1, 2, 4-Tricarboxylic Acid, Sodium salt (PBTCA•Na4) CAS No. 40372-66-5 Molecular Formula: C7H7O9P•Na4...
In this lesson, we examine the entire glycolytic pathway. We use as our theme the transfer of oxygen from phosphate to newly generated water. This explains why the standard stoichiometry of glycolysis found in textbooks show it generating two water molecules, and ties the information together with the analogous principles from substrate-level phosphorylation in the citric acid cycle and the relative differences in water consumption and carbon dioxide generation between fat and carbohydrate. As with our discussion of the citric acid cycle, we also reveal why the standard stoichiometry of glycolysis is misleading and why, when we account for atoms rather than molecules, we find glycolysis to be net water-neutral. For the full episode, go to chrismasterjohnphd.com/mwm/2/19 Sign up for MWM Pro for early access to content, enhanced keyword searching, self-pacing tools, downloadable audio and transcripts, a rich array of hyperlinked further reading suggestions, and a community with a forum for each lesson.
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annotations (the reliablity of the annotated protein expression using immunohistochemically (IH) stained on human tissues, the reliablity of the annotated protein expression in immunofluorescently (IF) stained human cell lines, tissue specificity (the distribution of antibody staining or protein expression in human cell types), cell line specificity (the distribution of RNA abundance in cell lines) and subcellular location (based on immunofluorescent staining of cell lines ...
Plants reconfigure their metabolic network under stress conditions. Changes of mitochondrial metabolism such as tricarboxylic acid (TCA) cycle and amino acid metabolism are reported in Arabidopsis roots but the exact molecular basis underlying this remains unknown. We here hypothesise the reassembly of enzyme protein complexes to be a molecular mechanism for metabolic regulation and tried in the present study to find out mitochondrial protein complexes which change their composition under oxidative stress by the combinatorial approach of proteomics and metabolomics. Arabidopsis seedlings were treated with menadione to induce oxidative stress. The inhibition of several TCA cycle enzymes and the oxidised NADPH pool indicated the onset of oxidative stress. In blue native/SDS-PAGE analysis of mitochondrial protein complexes the intensities of 18 spots increased and those of 13 spots decreased in menadione treated samples suggesting these proteins associate with, or dissociate from, protein complexes. Some
As a Computational Biology PhD student working with biological networks, I find the notion of "modularity" really ambiguous and troublesome - an opinion shared by other colleagues, even though the concept has been really successful, especially in the previous years. I suggest to assume a more critical perspective on the issue. For instance, the statement "Many organisms consist of modules" could be better formulated as "Modular parts can be recognized within organisms, at different organizational levels".. Specifically, I would like to point out that the example on the Citric Acid Cycle (a.k.a. Krebs Cycle, or TCA Cycle) is quite misleading. Refer to this resource for a diagramtic representation of the Krebs Cycle (human version): http://www.genome.ad.jp/dbget-bin/get_pathway?org_name=hsa&mapno=00020. First of all, the Krebs Cycle is composed just by a few reactions (10 reactions and 10 metabolites, neglecting some intermediates); therefore it cannot really be termed "a complex network"; it is ...
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ATP is synthesized in the mitochondria in the cells. Some of it is also synthesized in the cytoplasm. Lipids are broken down into fatty acids, proteins into amino acids, and carbohydrates into glucose.. This then undergoes a variety of oxidation-reduction reactions wherein the mitochondria degrade fatty acids, amino acids, and pyruvate. Pyruvate is the end product of glucose degradation in the cytoplasm. The final degradation leads to several intermediate compounds, as well as into the reduced electron carrier coenzymes NADH and FADH2. The intermediates enter the tricarboxylic acid (TCA) cycle or the citric acid cycle, also giving rise to NADH and FADH2.. These reduced electron carriers are themselves oxidized via the electron transport chain, with concomitant consumption of oxygen and ATP synthesis. This process is called the oxidative phosphorylation.. Each molecule of fatty acid releases over 100 molecules of ATP and each amino acid molecule releases almost forty ATP molecules. Two ATP ...
2 Phosphonobutane 1,2,4 Tricarboxylic Acid Phosphono Butanetricarboxylic Acid PBTCA PBTC Manufacturers Phosphono Butanetricarboxylic Acid GHS SDS MSDS Sheet
A global kinetic study of the central metabolism of Vero cells cultivated in a serum-free medium is proposed in the present work. Central metabolism including glycolysis, glutaminolysis, and tricarboxylic acid cycle (TCA) was demonstrated to be satur
... Brightwell Aquatics Florinaxis Carbon & Krebs by Brightwell Aquatics is a concentrated source of bioavailable carbon, Krebs cycle intermediates, humic and amino acids, and naturally occurring phytoho...
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Pyruvate carboxylase is a metabolic enzyme that fuels the tricarboxylic acid cycle with one of its intermediates and also participates in the first step of gluconeogenesis. This large enzyme is multif
Leveraging the strength of our DARs and senior engineering staff, MANNARINO is well positioned to provide EEDA support to our clients for both RTCA/DO-178B/C and RTCA/DO-254.. Working closely with our customers design assurance organization, our engineering staff supports EEDA activities through the review of life cycle data and the execution of desk and/or on-site supplier Stage of Involvement (SOI) audits. Reporting and compliance is executed per our customers approved EEDA processes to ensure a seamless execution of tasks.. ...
Metabolic enzyme. Molecular model of the enzyme aconitase, which is involved in the citric acid (or Krebs) cycle. The citric acid cycle is the process by which mitochondria convert glucose to energy. - Stock Image F009/5998
Organic acids play an integral role in plant primary metabolism, where they are involved in fundamental pathways such as, the tricarboxylic acid cycle, C3-, C4- and CAM-photosynthesis and the glyoxylate cycle. They also arise as products of the degradation of more reduced compounds and are interconverted in many plant tissues. Organic acids, such as malate, fumarate, lactate, and citrate, have essential functions in many cellular processes such as stomatal function, phosphorous acquisition, aluminium tolerance, communication with microorganisms, CO2 concentrating metabolism, temporary carbon storage, interchange of reductive power among subcellular compartments, and pH regulation. They also play a critical role in the regulation of plant development and growth, as well as in regulation of both primary and specialized metabolic pathways, some of which are involved in the response to both abiotic and biotic stress. Moreover, they play roles as signalling molecules, not only as allosteric regulators of
Abstract The levels of serum insulin, glucagon, and free fatty acids (FFA) and the tissue concentrations of hepatic cyclic AMP, long-chain acyl-CoA (LCA), adenine nucleotides, inorganic phosphate, the intermediates of the Embden-Meyerhof pathway, the citric acid cycle (including acetyl-CoA and free CoA), and the cytoplasmic and mitochondrial redox couples were determined in the rat 12, 24, and 48 h after food withdrawal and 5, 10, 20, 40, 60, and 120 min after the refeeding of glucose. Using the measured metabolite contents in the liver, the alterations in the concentration of malate, oxaloacetate, citrate, and α-ketoglutarate and the changes in the energy state of the adenine nucleotide system and the redox state of the NAD system were attributed to the cytoplasmic and mitochondrial compartments by applying established calculation methods. Glucose refeeding provoked significant alterations in all parameters investigated. These changes occurred within minutes, reversing the hormone and ...
On a low carb or no carb diet, our billions of cells in all our tissues and organs switch their energy mechanics from a process driven by glucose to one propelled by fatty acids and ketone bodies. The term ketosis simply means the state in which, in the absence of sufficient glucose, our liver synthesizes ketones from acetyl coenzyme A. However, even on a no carb, all meat high-fat diet, we will still be consuming some glucose in the form of glycogen stored in muscle and organ meats, and our livers will continue to convert some dietary amino acids into glucose, so blood sugar levels never hit zero on such a diet . But in such cases, the amounts produced will be minimal. Though our normal cells do just fine in the absence of carbohydrates, cancer cells, Dr. Thomas Seyfried claims, do not. These cells, he says can never use fatty acids of ketone bodies for any significant energy production, since the citric acid cycle and electron transport in them remain basically inactive. So, he proposes, as ...
Problem : How do molecules that cannot freely cross the inner mitochondrial membrane enter the matrix space to participate in the citric acid cycle and oxidative phosphorylation? They are transported across by specific transporter proteins ...
Transport in the respiratory chain of electrons from FADH2 and NADH will lead to the synthesis of five high-energy phosphates (Chapter 12) for each of the first seven acetyl-CoA molecules formed by β-oxidation of palmitate (7 × 5 = 35). A total of 8 mol of acetyl-CoA is formed, and each will give rise to 12 mol of ATP on oxidation in the citric acid cycle, making 8 × 12 = 96 mol. Two must be subtracted for the initial activation of the fatty acid, yielding a net gain of 129 mol of ATP per mole of palmitate, or 129 × 51.6* = 6656 kJ. This represents 68% of the free energy of combustion of palmitic acid. ...
Note the points at which amino acids. may enter the citric acid cycle. ... Another connection to amino acid metabolism. The Aspartate Malate Shunt ... - A free PowerPoint PPT presentation (displayed as a Flash slide show) on PowerShow.com - id: 152e16-YWM5M
Overview of catabolic pathways. Catabolism of glucose via glycolysis and the citric acid cycle . NADH. NADH, FADH 2. Converts: 1 glucose 2 pyruvate. Net reaction of glycolysis. +. Two molecules of ATP are produced Two molecules of NAD + are reduced to NADH. Slideshow 1773566 by cleo
Magnesiums most important function is the creation of energy in the trillions of cells making up our body. Magnesium is a cofactor in the production of ATP (adenosine triphosphate) via ATP synthase. ATP is manufactured in the mitochondria and it must be bound to a magnesium ion (MgATP) in order to be biologically active. There are 1,000-2,000 mitochondria in each human cell and ATP is made in each one through a series of 8 steps called the Krebs cycle. Whats remarkable about magnesium is that it is indispensable in 6 of those 8 steps.. We think of the Krebs cycle as a pathway for the breakdown of glucose but it takes pyruvate from the glycolysis cycle to make ATP energy molecules. The Krebs cycle is also necessary for the breakdown of all metabolites: sugars, amino acids and fatty acids. Each of these groups of molecules has a pathway that leads into the Krebs cycle. In addition, intermediates from the Krebs cycle can go the other direction and be used to synthesize amino acids and fatty ...
This lesson provides an overview of the basic objectives of using the citric acid cycle and the electron transport chain to make ATP. We start here because, no matter whether we burn protein, carbs, or fat, these two interrelated systems are what is shared in common. Watch the full lesson at chrismasterjohnphd.com/mwm/2/3 Sign up for MWM Pro for early access to content, enhanced keyword searching, self-pacing tools, downloadable audio and transcripts, a rich array of hyperlinked further reading suggestions, and a community with a forum for each lesson.  
BCHM 501 BIOCHEMISTRY I 3 credits Studies the structures and functions of proteins and enzymes such as amino acids and peptides; the metabolism of carbohydrates and lipids, the respiratory chain, oxidative phosphorylation, citric acid cycle, glycolysis, ketogenesis and the synthesis of cholesterol. Included are the biosynthesis of essential and non-essential amino acids and the catabolism of amino acids. Prerequisite: Biology and Chemistry. ...
Global Citric Acid Market Citric acid is an organic weak acid, which is a vital intermediary in metabolism. Naturally, citric acid is found in citrus veget
How is antibodies to citric acid muscle extract abbreviated? a-CAE stands for antibodies to citric acid muscle extract. a-CAE is defined as antibodies to citric acid muscle extract very rarely.
High Quality Citric Acid Anhydrous Supplier, FOODCHEM is Top Citric Acid Anhydrous Supplier and Manufacturer in China for more than 10 years, Buy Citric Acid Anhydrous Food Grade and Feed Grade at Foodchem
Coenzyme Q10 is present in the cell membranes of all cells within our overall body, particularly while in the inner mitochondrial membranes, and it is especially concentrated in extremely Energetic organs like the heart, lungs, kidneys, spleen, and adrenal glands. The mitochondria develop large amounts of adenosine triphosphate (ATP), which aids cells perform perform. For the reason that manufacture of adenosine triphosphate (ATP) from the mitochondria is understood to generate many damaging oxygen radicals, coenzyme Q10 serves an antioxidant operate in that spot by neutralising radicals. Coenzyme Q10 is usually required by a important enzyme during the Krebs cycle (Citric Acid Cycle), which converts equally carbohydrates and fat into usable Strength for your cell. Does Isotonix Coenzyme Q10 incorporate pork or pork products and solutions ...
Biotin is essential for all organisms as it is involved in cell growth, the production of fatty acids, the metabolism of fats and amino acids, the citric acid cycle, the transfer of carbon dioxide, and in gluconeogensis.
MountainRoseHerbs.com, Brambleberry.com and Amazon.com sell citric acid, offering a variety of size options from 1 pound to 55 pound bags, as of June 2015. People use citric acid for cooking,...
In North America, Cargill is a supplier of bulk citric acid - available as a liquid or anhydrous product - which is an additive used to enhance flavors.
FOODCHEM is a professional supplier and manufacturer of Buy Citric Acid Anhydrous China, with 11 years experience in exporting more than 100 countries.
gluconeogenesis: Formation in living cells of glucose and other carbohydrates from other classes of compounds. These compounds include lactate and pyruvate; the compounds of the tricarboxylic acid...
In this Behind the paper: blog, I discuss the rationale for searching non-enzymatic, metabolism like chemical networks, and the circumstances that led to their discovery. I can also not omit to also make reference to some of the original reactions to this work,
This short slide set explains the uniformity of the Krebs cycle across all life using evolutionary theory. Save the slide set to your computer to view the explanation and notes that go along with each slide.. Author/Source: ...
A major finding in the current study was the ability of the muscle to maintain TCA cycle intermediate (TCAi) concentrations and cellular energy charge during exercise in spite of AMPD activity being less than 1 % of control values. This finding demonstrates the utility of using an inborn error of metabolism to unravel a fundamental question in muscle physiology, namely, that the PNC is not required for TCA cycle anaplerosis. From a clinical perspective, the main finding in this study is that patients with less than 1 % residual AMPD activity were not markedly different from subjects with normal AMPD activity in their tolerance for progressive cycle ergometry exercise.. One conceivable consequence of AMPD deficiency would be an impairment of the PNC with a resultant attenuation of TCAi anaplerosis (Sabina et al. 1980; Flanagan et al. 1986). It has previously been demonstrated that the total muscle TCAi content increased severalfold during the initial minutes of moderate to intense contraction, ...
The utilisation of L-malate and the effect of glucose concentration on malate utilisation under semi-anaerobic conditions were investigated in three yeasts unable to grow on malate as sole carbon source (Saccharomyces cerevisiae, Schizosaccharomyces malidevorans, Zygosaccharomyces bailii) and two yeasts able to utilise the TCA cycle intermediate as sole carbon source (Pichia stipitis and Pachysolen tannophilus). Utilisation of malate by both Schiz. malidevorans and Z. bailii was reduced at high and low levels of glucose. In the absence of glucose, P. stipitis and Pa. tannophilus utilised malate rapidly; however, their utilisation was drastically reduced in the presence of glucose, suggesting that malate utilisation is under catabolite repression.
Tight coupling between cytosolic and mitochondrial metabolism is key for GSIS (glucose-stimulated insulin secretion). In the present study we examined the regulatory contribution of PDH (pyruvate dehydrogenase) kinase 1, a negative regulator of PDH, to metabolic coupling in 832/13 clonal beta-cells. Knockdown of PDH kinase 1 with siRNA (small interfering RNA) reduced its mRNA (,80 %) and protein level (,40 %) after 72 h. PDH activity, glucose-stimulated cellular oxygen consumption and pyruvate-stimulated mitochondrial oxygen consumption increased 1.7- (P , 0.05), 1.6- (P , 0.05) and 1.6-fold (P , 0.05) respectively. Gas chromatography/MS revealed an altered metabolite profile upon silencing of PDH kinase 1, determined by increased levels of the tricarboxylic acid cycle intermediates malate, fumarate and alpha-ketoglutarate. These metabolic alterations were associated with exaggerated GSIS (5-fold compared with 3.1-fold in control cells; P , 0.01). Insulin secretion, provoked by leucine and ...
In crude cell extracts of the ectomycorrhizal fungus, Suillus bovinus, activities of citrate synthase. aconitase, isocitrate dehydrogenase. succinate dehydrogenase. fumarase, and malate dehydrogenase have been proved and analyzed. Citrate synthase exhibited high affinities for both its substrates: oxaloacetate: (K-m = 0.018 mM) and acetyl-CoA (K-m = 0.014 mM). Aconitase showed better affinity for isocitrate (K-m = 0.62 mM) than for citrate (K-m = 3.20 mM). Analysis of isocitrate dehydrogenase revealed only small maximum activity (60 nmol x mg protein(-1) x min(-1)), the enzyme being exclusively NADP(+)-dependent. Using the artificial electron acceptor dichlorophenol indophenol, activity and substrate affinity of succinate dehydrogenase were rather poor. Fumarase proved Fe2+-independent. Its affinity for malate was found higher (K-m = 1.19 mM) than that for fumarate (K-m = 2.09 mM). High total activity of malate dehydrogenase could be separated by native PAGE into a slowly running species of ...
Isocitrate dehydrogenases catalyze the oxidative decarboxylation of isocitrate to 2-oxoglutarate. These enzymes belong to two distinct subclasses, one of which utilizes NAD(+) as the electron acceptor and the other NADP(+). Five isocitrate dehydrogenases have been reported: three NAD(+)-dependent isocitrate dehydrogenases, which localize to the mitochondrial matrix, and two NADP(+)-dependent isocitrate dehydrogenases, one of which is mitochondrial and the other predominantly cytosolic. NAD(+)-dependent isocitrate dehydrogenases catalyze the allosterically regulated rate-limiting step of the tricarboxylic acid cycle. Each isozyme is a heterotetramer that is composed of two alpha subunits, one beta subunit, and one gamma subunit. The protein encoded by this gene is the gamma subunit of one isozyme of NAD(+)-dependent isocitrate dehydrogenase. This gene is a candidate gene for periventricular heterotopia. Several alternatively spliced transcript variants of this gene have been described, but only ...
Evasion of complement-mediated killing is a common phenotype for many different types of pathogens, but the mechanism is still poorly understood. Most of the clinic isolates of Edwardsiella tarda, an important pathogen infecting both of human and fish, are commonly found serum-resistant. To explore the potential mechanisms, we applied GC-MS based metabolomics approaches to profile the metabolomes of E. tarda EIB202 in the presence or absence of serum stress. We found that TCA cycle was greatly enhanced in the presence of serum. The QRT-PCR and enzyme activity assays validated this result. Furthermore, exogenous succinate that promoting TCA cycle increased serum resistance, while TCA cycle inhibitors (bromopyruvate and propanedioic acid) that inhibit TCA cycle, attenuated serum resistance. Moreover, the enhanced TCA cycle increased membrane potential, thus decreased the formation of membrane attack complex at cell surface, resulting serum resistance. These evidences suggested a previously unknown
The central metabolic pathways are a glycolytic pathway, a pentose phosphate pathway, and the citric acid cycle (Fig. 1). Conversion of glucose to pyruvate via the nonphosphorylating Entner-Doudoroff pathway produces no net energy (19). Genes for most enzymes, except gluconate dehydratase, are present (Sso3204, 3197, 3194, 0666, 0913, 0981). Conversion of pentose substrates (xylose, arabinose) is predicted to proceed via the pentose phosphate pathway, or a variant thereof. However, only genes encoding ribose-5-P isomerase (Sso0978) and transketolase (Sso0297 and 0299) are assigned. In contrast, all citric acid cycle genes are present (Sso1077, 1095, 2182, 2356 to 2359, 2482, 2483, 2585, 2589, 2815, 2816, 2863).. It is striking that NAD+ is used rarely as an electron acceptor in some central metabolic redox reactions. Both glucose dehydrogenase and glyceraldehyde dehydrogenase are reported to reduce NADP+ specifically. Moreover, glyceraldehyde-3-phosphate dehydrogenase, isocitrate dehydrogenase, ...
Citric acid (citrate) is a weak acid that is formed in the tricarboxylic acid cycle or that may be introduced with diet. The evaluation of plasma citric acid is scarcely used in the diagnosis of animal diseases. On the contrary urinary citrate excretion is a common tool in the differential diagnosis of kidney stones, renal tubular acidosis and it plays also a role in bone diseases. The importance of hypocitraturia should be considered with regard to bone mass, urine crystallization and urolithiasis. (PMID 12957820 ) The secretory epithelial cells of the prostate gland of animals and other animals posses a unique citrate-related metabolic pathway regulated by testosterone and prolactin. This specialized hormone-regulated metabolic activity is responsible for the major prostate function of the production and secretion of extraordinarily high levels of citrate. The key regulatory enzymes directly associated with citrate production in the prostate cells are mitochondrial aspartate aminotransferase, ...
Citric acid (citrate) is a weak acid that is formed in the tricarboxylic acid cycle or that may be introduced with diet. The evaluation of plasma citric acid is scarcely used in the diagnosis of human diseases. On the contrary urinary citrate excretion is a common tool in the differential diagnosis of kidney stones, renal tubular acidosis and it plays also a role in bone diseases. The importance of hypocitraturia should be considered with regard to bone mass, urine crystallization and urolithiasis. (PMID 12957820 ) The secretory epithelial cells of the prostate gland of humans and other animals posses a unique citrate-related metabolic pathway regulated by testosterone and prolactin. This specialized hormone-regulated metabolic activity is responsible for the major prostate function of the production and secretion of extraordinarily high levels of citrate. The key regulatory enzymes directly associated with citrate production in the prostate cells are mitochondrial aspartate aminotransferase, ...

Molecular properties, genetics, and biosynthesis of |em|Bacillus subtilis|/em| succinate dehydrogenase complexMolecular properties, genetics, and biosynthesis of |em|Bacillus subtilis|/em| succinate dehydrogenase complex

The citric acid cycle enzyme succinate dehydrogenase (SDH) is a membrane-bound iron-sulfur flavoprotein. Mitochondrial and ... The citric acid cycle enzyme succinate dehydrogenase (SDH) is a membrane-bound iron-sulfur flavoprotein. Mitochondrial and ... The citric acid cycle enzyme succinate dehydrogenase (SDH) is a membrane-bound iron-sulfur flavoprotein. Mitochondrial and ...
more infohttps://lup.lub.lu.se/search/publication/cf46fba3-5796-4634-acdf-dfa4d578d20e

Oxaloacetic Acid - Oxaloacetic Acid Suppliers, Buyers, Wholesalers and Manufacturers - ecplaza.netOxaloacetic Acid - Oxaloacetic Acid Suppliers, Buyers, Wholesalers and Manufacturers - ecplaza.net

Oxaloacetic Acid manufacturers, suppliers ☆ Oxaloacetic Acid buyers, importers, wholesalers, distributors ... start a new cycle. It is a part of the citric acid cycle. CAS number:.... Wuxi Cima Science Co., Ltd ... Citric acid. The citric acid is in the tricarboxylic acid circulation the tricarboxylic acid compound which first synthesizes ... Oxaloacetate Acid. Product name: oxaloacetate acid Introduction: oxaloacetate is catalyzed by malate dehydrogenase malic acid ...
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Isocitrate dehydrogenase [NAD] subunit gamma, mitochondrialIsocitrate dehydrogenase [NAD] subunit gamma, mitochondrial

Pyruvate metabolism and Citric Acid (TCA) cycle 48 The citric acid (TCA) cycle and respiratory electron transport 168 ... NAD+ + Isocitric acid = NADH + 2-Oxo-glutaric acid + CO2 ( Citrate cycle ) 3 ... dependent isocitrate dehydrogenases catalyze the allosterically regulated rate-limiting step of the tricarboxylic acid cycle. ... superpathway of conversion of glucose to acetyl CoA and entry into the TCA cycle 46 ...
more infohttps://pharos.nih.gov/idg/targets/P51553

Category:Citric acid cycle - Wikimedia CommonsCategory:Citric acid cycle - Wikimedia Commons

Krebs cycle, TCA cycle, GO:0006099, citric acid cycle (en); حلقة حمض الليمون, دوره حمض الستريك, دورة الحموض ثلاثية الكربوكسيل, ... Krebs cycle, tricarboxylic acid cycle, TCA cycle (en-ca); 크레브스 회로, TCA회로, 구연산 회로, 크렙스 회로, 시트르산 회로 (ko); TCAサイクル, TCAC, クレブス回路, ... Krebs cycle, tricarboxylic acid cycle, TCA cycle (en-gb); چرخه تری‌کربوکسیلیک اسید, چرخه کربس, چرخهٔ اسید سیتریک, کریپس سایکل, ... Media in category "Citric acid cycle". The following 180 files are in this category, out of 180 total. ...
more infohttps://commons.wikimedia.org/wiki/Category:Citric_acid_cycle

Citric acid cycle - WikipediaCitric acid cycle - Wikipedia

The citric acid cycle (CAC) - also known as the TCA cycle (tricarboxylic acid cycle) or the Krebs cycle[1][2] - is a series of ... Citric acid cycle variants at MetaCyc. *Pathways connected to the citric acid cycle at Kyoto Encyclopedia of Genes and Genomes ... Citric Acid Cycle. Boston: Academic Press. ISBN 0-12-181870-5.. *^ Kay J, Weitzman PD (1987). Krebs citric acid cycle: half a ... However, because of the role of the citric acid cycle in anabolism, they might not be lost, since many citric acid cycle ...
more infohttps://en.m.wikipedia.org/wiki/Krebs_cycle

citric acid cycle (thing) by BioTech - Everything2.comcitric acid cycle (thing) by BioTech - Everything2.com

A complex series of reactions following glycolysis in aerobic respiration that convert pyruvic acid into hydrogen, carbon ... citric acid cycle (thing). See all of citric acid cycle, no other writeups in this node. ... More commonly known as the Krebs cycle, and less commonly known as the tricarboxylic acid cycle. ... A complex series of reactions following glycolysis in aerobic respiration that convert pyruvic acid into hydrogen, carbon ...
more infohttps://everything2.com/user/BioTech/writeups/citric+acid+cycle

Krebs / citric acid cycle (video) |
Khan AcademyKrebs / citric acid cycle (video) | Khan Academy

Overview of the Krebs or citric acid cycle, which is a series of reactions that takes in acetyl CoA and produces carbon dioxide ... or the Krebs cycle or the citric acid cycle gets credit for this step. But its really a preparation step for the Krebs cycle. ... The Krebs cycle, or the citric acid cycle. And that actually takes place in the inner membrane, or I should say the inner space ... Now, in the citric acid cycle, or in the Krebs cycle, well first we have our pyruvate oxidation. That produced one NADH. But ...
more infohttps://www.khanacademy.org/science/biology/cellular-respiration-and-fermentation/pyruvate-oxidation-and-the-citric-acid-cycle/v/krebs-citric-acid-cycle

Citric Acid Cycle - Proteopedia, life in 3DCitric Acid Cycle - Proteopedia, life in 3D

The Citric Acid Cycle is a series of enzyme catalyzed reactions which are critical in cellular respiration. In this cycle, ... To view automatically seeded indices concerning Citric Acid Cycle See: *Citric Acid Cycle ...
more infohttp://proteopedia.org/wiki/index.php/Citric_Acid_Cycle

The Citric Acid Cycle - Course HeroThe Citric Acid Cycle - Course Hero

This lesson provides helpful information on The Citric Acid Cycle in the context of Cellular Respiration to help students study ... The Citric Acid Cycle. The citric acid cycle consists of a series of steps used to catalyze products following the oxidation of ... Steps of the Citric Acid Cycle. The citric acid cycle starts after the oxidation of pyruvate. It consists of eight sequential ... Citric Acid Cycle Net Reaction. The citric acid cycle uses multiple reactions for the release of energy. ...
more infohttps://www.coursehero.com/sg/introduction-to-biology/the-citric-acid-cycle/

Glicerina biotecnologia | Glycolysis | Citric Acid CycleGlicerina biotecnologia | Glycolysis | Citric Acid Cycle

acid, lactic acid, betaine, potassium sulfate, l-pyroglutamic acid,. and free flowing distillers dry grain and solubles or a ... amino acids [25,32]. Furthermore, aerobic oxidation of. pyruvatevia pyruvate dehydrogenase and the TCA cycle. enzymesproduces ... acid that is excreted from the cells cannot diffuse back into. the cells, since the ionic form of acetic acid predominates. at ... amino acid synthesis [25]. It has also been reported that the. activity of ADH is decreased when amino acids rather than. ...
more infohttps://www.scribd.com/document/259508868/Glicerina-biotecnologia

Glycolysis & Respiration | Cellular Respiration | Citric Acid CycleGlycolysis & Respiration | Cellular Respiration | Citric Acid Cycle

6 NADH from the Krebs cycle allow the production of 15 ATP. 2 FADH from Krebs cycle allow the production of 3 ATP. e eukaryotes ... Krebs cycle. cycle.. In eukaryotes, all steps. of respiration occur in. the mitochondrion.. 10 ... and the Krebs cycle are used to produce ATP through. chemiosmosis. O2 is the final acceptor of high energy electrons.. In ... Krebs Cycle:. 2 Acetyl Co-A 4 CO2 + 2 ATP + 6 NADH + 2 FADH. Electron transport system (ETS):. 2 NADH from glycolysis allow ...
more infohttps://pt.scribd.com/document/328717229/Glycolysis-Respiration

Citric Acid Cycle | Profiles RNSCitric Acid Cycle | Profiles RNS

"Citric Acid Cycle" by people in this website by year, and whether "Citric Acid Cycle" was a major or minor topic of these ... "Citric Acid Cycle" is a descriptor in the National Library of Medicines controlled vocabulary thesaurus, MeSH (Medical Subject ... Citric Acid Cycle*Citric Acid Cycle. *Citric Acid Cycles. *Cycle, Citric Acid ... Below are the most recent publications written about "Citric Acid Cycle" by people in Profiles. ...
more infohttps://profiles.umassmed.edu/display/120501

Citric acid cycles Synonyms, Citric acid cycles Antonyms | Thesaurus.comCitric acid cycles Synonyms, Citric acid cycles Antonyms | Thesaurus.com

Synonyms for citric acid cycles at Thesaurus.com with free online thesaurus, antonyms, and definitions. Dictionary and Word of ... citric acid cycles. star. see definition of citric acid cycles show all. noun. ... More words related to citric acid cycles. Krebs cycle noun. series of enzymatic reactions ... citric acid cycle Relevance Relevance ranks synonyms and suggests the best matches based on how closely a synonyms sense ...
more infohttp://www.thesaurus.com/browse/citric%20acid%20cycles

Sandwalk: Biochemistry on the Web: The Citric Acid CycleSandwalk: Biochemistry on the Web: The Citric Acid Cycle

find one single website that correctly shows the reactions of the citric acid cycle with all the correct substrates and ... Enzymes of the Citric Acid Cycle. citrate synthase [EC 2.3.3.1]. aconitase [EC 4.2.1.3]. isocitrate dehydrogenase [EC 1.1.1.41 ... In the direction of the citric acid cycle the electrons are passed from succinate to FAD+ to three Fe-S clusters and then to ... Here are some websites that discuss the Citric Acid Cycle [Krebs animation][Wikipedia]. This is one of the fundamental ...
more infohttp://sandwalk.blogspot.com/2008/11/biochemistry-on-web-citric-acid-cycle.html

Structural Biochemistry/Krebs Cycle (Citric Acid cycle) - Wikibooks, open books for an open worldStructural Biochemistry/Krebs Cycle (Citric Acid cycle) - Wikibooks, open books for an open world

Citric Acid Cycle[edit]. Other name for citric acid cycle is tricarboxylic acid (TCA) cycle or the Krebs cycle. The citric acid ... Regulatory Enzyme in Citric Acid Cycle[edit]. In animal cells, the rate of citric acid cycle is regulated to fitted the ... Structural Biochemistry/Krebs Cycle (Citric Acid cycle). From Wikibooks, open books for an open world ... Citric Acid Cycle Links to Glycolysis by Pyruvate Dehydrogenase[edit]. Carbohydrates are mostly processed by glycolysis into ...
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Glycolysis & the Citric Acid Cycle - Video & Lesson Transcript | Study.comGlycolysis & the Citric Acid Cycle - Video & Lesson Transcript | Study.com

The Citric Acid Cycle. Once weve finished with glycolysis, we can move onto stage two of respiration, the citric acid cycle, ... Glycolysis produces the molecules that are processed by the citric acid cycle. The citric acid cycle occurs in the mitochondria ... Still, this is a productive cycle, and it actually isnt over. Some of the molecules produced by the citric acid cycle will ... Just as with glycolysis, the citric acid cycle has two phases. In the first phase, pyruvate is oxidized to form Acetyl CoA. ...
more infohttps://study.com/academy/lesson/glycosis-the-citric-acid-cycle.html

Citric acid cycle (TCA cycle) | Biology | Catabolism schematic - Biochemical diagram | Chart Of TricarboxylicCitric acid cycle (TCA cycle) | Biology | Catabolism schematic - Biochemical diagram | Chart Of Tricarboxylic

Citric acid cycle. Wikipedia] ,br,This biochemical diagram example shows metabolic pathways map of citric acid cycle reactions ... creativecommons.org/licenses/by/3.0/deed.en] ,br,The metabolic pathway map example Citric acid cycle (TCA cycle) was created ... tricarboxylic acid cycle, TCA cycle, Krebs cycle) is a series of chemical reactions used by all aerobic organisms to generate ... br,This sample was redesigned from the Wikimedia Commons file: TCA cycle.svg. [commons.wikimedia.org/wiki/File:TCA_cycle.svg] , ...
more infohttp://www.conceptdraw.com/examples/chart-of-tricarboxylic

The Citric Acid Cycle - The WikiPremed MCAT CourseThe Citric Acid Cycle - The WikiPremed MCAT Course

The topic under discussion here is The Citric Acid Cycle - The WikiPremed MCAT Course ... fatty acids, and carbohydrates, are ultimately oxidized in aerobic metabolism by means of the citric acid cycle. Most enter the ... Kimballs Biology Pages - The Citric Acid Cycle. Online Biology Book - Aerobic Respiration. Basic introduction to aerobic ... The Citric Acid Cycle including the initial pyruvate mobilization is a series of reactions oxidizing the pyruvate from ...
more infohttp://www.wikipremed.com/classic/mcat_course.php?code=0403010600000000

Citric acid cycle (TCA cycle) | Design elements - TCA cycle | Biology Symbols | Citric Acid CycleCitric acid cycle (TCA cycle) | Design elements - TCA cycle | Biology Symbols | Citric Acid Cycle

Citric acid cycle. Wikipedia] ,br,This biochemical diagram example shows metabolic pathways map of citric acid cycle reactions ... creativecommons.org/licenses/by/3.0/deed.en] ,br,The metabolic pathway map example Citric acid cycle (TCA cycle) was created ... tricarboxylic acid cycle, TCA cycle, Krebs cycle) is a series of chemical reactions used by all aerobic organisms to generate ... br,This sample was redesigned from the Wikimedia Commons file: TCA cycle.svg. [commons.wikimedia.org/wiki/File:TCA_cycle.svg] , ...
more infohttp://www.conceptdraw.com/examples/citric-acid-cycle

Search: protein class:Citric acid cycle related proteins - The Human Protein AtlasSearch: protein class:Citric acid cycle related proteins - The Human Protein Atlas

Cell cycle intensity correlation. Cell cycle spatial correlation. Cell cycle biologically. Custom data cell cycle dependant. - ... Citric acid cycle related proteins. Disease related genes. Enzymes. FDA approved drug targets. G-protein coupled receptors. ... Citric acid cycle related proteins. Disease related genes. Enzymes. Potential drug targets. Predicted intracellular proteins. ... Citric acid cycle related proteins. Disease related genes. Enzymes. Potential drug targets. Predicted intracellular proteins. ...
more infohttps://www.proteinatlas.org/search/protein_class:Citric+acid+cycle+related+proteins

WikiPremed MCAT Course - Regulation of the Citric Acid CycleWikiPremed MCAT Course - Regulation of the Citric Acid Cycle

University of Waterloo - Regulation of the citric acid cycle.. Good short synopsis.. ...
more infohttp://www.wikipremed.com/mcat_course.php?code=0403020200000000

Citric acid cycle - WikipediaCitric acid cycle - Wikipedia

... of the citric acid cycle at Smith College Citric acid cycle variants at MetaCyc Pathways connected to the citric acid cycle at ... The citric acid cycle (CAC) - also known as the tricarboxylic acid (TCA) cycle or the Krebs cycle - is a series of chemical ... However, because of the role of the citric acid cycle in anabolism, they might not be lost, since many citric acid cycle ... Citric Acid Cycle. Boston: Academic Press. ISBN 0-12-181870-5. Krebs HA, Weitzman PD (1987). Krebs citric acid cycle: half a ...
more infohttps://en.wikipedia.org/wiki/Citric_acid_cycle

2009--Real-time Assessment of Krebs Cycle Metabolism Using | Citric Acid Cycle | Glycolysis2009--Real-time Assessment of Krebs Cycle Metabolism Using | Citric Acid Cycle | Glycolysis

Real-time Assessment of Krebs Cycle Metabolism Using - Free download as PDF File (.pdf), Text File (.txt) or read online for ... flux through citric acid cycle pathways in perfused heart by 13C. NMR spectroscopy. FEBS Lett. 212, 58 62. Malloy, C. R., ... reduced fatty acid oxidation, which raises the question. as to how Krebs cycle flux and cardiac energetics can be. maintained ... 29). Also, fatty acid metabolism contributes to Krebs. cycle recovery following ischemia (28, 37). Therefore,. these ...
more infohttps://www.scribd.com/document/291017016/2009-Real-time-Assessment-of-Krebs-Cycle-Metabolism-Using

The Citric Acid Cycle and Intermediary Catalysts | ENCOGNITIVE.COMThe Citric Acid Cycle and Intermediary Catalysts | ENCOGNITIVE.COM

The Citric Acid Cycle and Intermediary Catalysts. Tagged: *Citric acid, oxalic acid, and phytic acid ... The "Bio-Catalyst" products contain all the intermediates of the citric acid cycle. The citric acid cycle works much like a ... In the first stage, Gylcolysis, glucose is broken down to pyruvic acid. In the second stage, the Citric Acid Cycle pyruvic acid ... The citric acid cycle is a sequential process; one step follows the next. Any disruption in the cycle stops the process. The ...
more infohttp://encognitive.com/node/13425

Citric Acid Cycle or Krebs Cycle - DnaTube.com - Scientific Video and Animation SiteCitric Acid Cycle or Krebs Cycle - DnaTube.com - Scientific Video and Animation Site

... citric acid is first consumed and then regenerated in a sequence of reactions. All aerobic organisms use this cycle to generate ... Citric Acid Cycle or Krebs Cycle In this cycle,citric acid is first consumed and then regenerated in a sequence of reactions. ... Tags: citric acid cycle cell biology Uploaded by: sana ( Send Message ) on 27-05-2009. Dnatube suggest users to have interest ...
more infohttps://www.dnatube.com/video/2355/Citric-Acid-Cycle-or-Krebs-Cycle
  • The NADH and FADH 2 generated by the citric acid cycle are, in turn, used by the oxidative phosphorylation pathway to generate energy-rich ATP. (wikipedia.org)
  • In addition to serving as the primary pathway in oxidative metabolism for the degradation of nutrient molecules, ultimately to give rise to ATP through electron transport, the citric acid cycle is a major source of precursors for the synthesis of biological molecules. (wikipremed.com)
  • This is the time of the year when I challenge the students in my introductory biochemistry class to find one single website that correctly shows the reactions of the citric acid cycle with all the correct substrates and products (including water and protons). (blogspot.com)
  • Biology solution provides 3 libraries with large quantity of vector biology symbols: Biochemistry of Metabolism Library, Carbohydrate Metabolism Library, Citric Acid Cycle (TCA Cycle) Library. (conceptdraw.com)
  • Biology solution offers 3 libraries of ready-to-use predesigned biology symbols and vector clipart to make your biology drawing and biology illustration making fast and easy: Carbohydrate Metabolism Library, Biochemistry of Metabolism Library, Citric Acid Cycle (TCA Cycle) Library. (conceptdraw.com)
  • Through catabolism of sugars, fats, and proteins, the two-carbon organic product acetyl-CoA (a form of acetate) is produced which enters the citric acid cycle. (wikipedia.org)
  • The NADH generated by the citric acid cycle is fed into the oxidative phosphorylation (electron transport) pathway. (wikipedia.org)
  • This is because oxygen is needed later, during the electron transport chain, which creates the ATP and NADH used to drive this cycle. (coursehero.com)
  • While direct substrate phosphorylation does occur to an extent in the citric acid cycle, the processes of the electron transport chain yield a great deal of energy, forming most of the ATPs per glucose in aerobic respiration. (wikipremed.com)
  • An integral part of the citric acid cycle is the electron transport system. (encognitive.com)
  • If lactate or propionate were added, malate and citrate accumulated indicating utilization of anaplerotic pathways for the citric acid cycle. (mysciencework.com)
  • To determine the temporal relationship between changes in contractile performance and flux through the citric acid cycle in hearts oxidizing acetoacetate, we perfused isolated working rat hearts with either glucose or acetoacetate (both 5 mM) and freeze-clamped the tissue at defined times. (mysciencework.com)
  • The product of this reaction, acetyl-CoA, is the starting point for the citric acid cycle. (wikipedia.org)
  • One of the primary sources of acetyl-CoA is from the breakdown of sugars by glycolysis which yield pyruvate that in turn is decarboxylated by the enzyme pyruvate dehydrogenase generating acetyl-CoA according to the following reaction scheme: CH3C(=O)C(=O)O−pyruvate + HSCoA + NAD+ → CH3C(=O)SCoAacetyl-CoA + NADH + CO2 The product of this reaction, acetyl-CoA, is the starting point for the citric acid cycle. (wikipedia.org)
  • Per reaction cycle, 1 acetyl-CoA is transformed into 2 CO 2 . (lecturio.com)
  • In this reaction step, the first oxidation reaction and the first decarboxylation of the citric acid cycle occur - with the formation of 1 NADH + H + and the release of CO 2 . (lecturio.com)
  • The reactions of the cycle also convert three equivalents of nicotinamide adenine dinucleotide (NAD + ) into three equivalents of reduced NAD + (NADH), one equivalent of flavin adenine dinucleotide (FAD) into one equivalent of FADH 2 , and one equivalent each of guanosine diphosphate (GDP) and inorganic phosphate (P i ) into one equivalent of guanosine triphosphate (GTP). (wikipedia.org)
  • As the final stage of food utilization, the citric acid cycle is primarily responsible for many anabolic and catabolic processes of the human body. (lecturio.com)
  • The shapes example "Design elements - TCA cycle" is included in the Biology solution from the Science and Education area of ConceptDraw Solution Park. (conceptdraw.com)
  • The citric acid cycle provides the majority, 90 percent, of energy used by aerobic human cells. (wikibooks.org)
  • All aerobic organisms use this cycle to generate energy. (dnatube.com)
  • Practice: The citric acid cycle requires oxygen indirectly, because oxygen is necessary for what to occur? (clutchprep.com)
  • The end result is the production of NADH and the reformation of oxaloacetate, which is then recycled to start the cycle over again. (coursehero.com)
  • Exam4Notes - Chapter 11 The Citric Acid Cycle Learning. (coursehero.com)
  • The overall yield of energy-containing compounds from the TCA cycle is three NADH, one FAD(2H), and one GTP. (wikipedia.org)
  • If there is a lack of oxygen at this end step, the whole citric acid cycle stops. (encognitive.com)
  • Because the citric acid cycle is so fundamental to energy production, it's no wonder that one feels sick and run down when there is a disturbance in ATP production. (encognitive.com)
  • In eukaryotic cells, the citric acid cycle occurs in the matrix of the mitochondrion. (wikipedia.org)
  • The citric acid cycle occurs as a closed loop. (coursehero.com)