Polyunsaturated side-chain quinone derivative which is an important link in the electron transport chain of green plants during the photosynthetic conversion of light energy by photophosphorylation into the potential energy of chemical bonds.
At low concentrations, this compound inhibits reduction of conventional hydrophilic electron acceptors, probably acting as a plastoquinone antagonist. At higher concentrations, it acts as an electron acceptor, intercepting electrons either before or at the site of its inhibitory activity.
A pre-emergent herbicide.
A large multisubunit protein complex found in the THYLAKOID MEMBRANE. It uses light energy derived from LIGHT-HARVESTING PROTEIN COMPLEXES to catalyze the splitting of WATER into DIOXYGEN and of reducing equivalents of HYDROGEN.
Membranous cisternae of the CHLOROPLAST containing photosynthetic pigments, reaction centers, and the electron-transport chain. Each thylakoid consists of a flattened sac of membrane enclosing a narrow intra-thylakoid space (Lackie and Dow, Dictionary of Cell Biology, 2nd ed). Individual thylakoids are interconnected and tend to stack to form aggregates called grana. They are found in cyanobacteria and all plants.
The synthesis by organisms of organic chemical compounds, especially carbohydrates, from carbon dioxide using energy obtained from light rather than from the oxidation of chemical compounds. Photosynthesis comprises two separate processes: the light reactions and the dark reactions. In higher plants; GREEN ALGAE; and CYANOBACTERIA; NADPH and ATP formed by the light reactions drive the dark reactions which result in the fixation of carbon dioxide. (from Oxford Dictionary of Biochemistry and Molecular Biology, 2001)
A protein complex that includes CYTOCHROME B6 and CYTOCHROME F. It is found in the THYLAKOID MEMBRANE and plays an important role in process of PHOTOSYNTHESIS by transferring electrons from PLASTOQUINONE to PLASTOCYANIN or CYTOCHROME C6. The transfer of electrons is coupled to the transport of PROTONS across the membrane.
Hydrocarbon rings which contain two ketone moieties in any position. They can be substituted in any position except at the ketone groups.
Porphyrin derivatives containing magnesium that act to convert light energy in photosynthetic organisms.
Plant cell inclusion bodies that contain the photosynthetic pigment CHLOROPHYLL, which is associated with the membrane of THYLAKOIDS. Chloroplasts occur in cells of leaves and young stems of plants. They are also found in some forms of PHYTOPLANKTON such as HAPTOPHYTA; DINOFLAGELLATES; DIATOMS; and CRYPTOPHYTA.
The process by which ELECTRONS are transported from a reduced substrate to molecular OXYGEN. (From Bennington, Saunders Dictionary and Encyclopedia of Laboratory Medicine and Technology, 1984, p270)
A large multisubunit protein complex that is found in the THYLAKOID MEMBRANE. It uses light energy derived from LIGHT-HARVESTING PROTEIN COMPLEXES to drive electron transfer reactions that result in either the reduction of NADP to NADPH or the transport of PROTONS across the membrane.
Protein complexes that take part in the process of PHOTOSYNTHESIS. They are located within the THYLAKOID MEMBRANES of plant CHLOROPLASTS and a variety of structures in more primitive organisms. There are two major complexes involved in the photosynthetic process called PHOTOSYSTEM I and PHOTOSYSTEM II.
That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.
A genus of EUKARYOTES, in the phylum EUGLENIDA, found mostly in stagnant water. Characteristics include a pellicle usually marked by spiral or longitudinal striations.
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).
A family of phylloquinones that contains a ring of 2-methyl-1,4-naphthoquinone and an isoprenoid side chain. Members of this group of vitamin K 1 have only one double bond on the proximal isoprene unit. Rich sources of vitamin K 1 include green plants, algae, and photosynthetic bacteria. Vitamin K1 has antihemorrhagic and prothrombogenic activity.
Complexes containing CHLOROPHYLL and other photosensitive molecules. They serve to capture energy in the form of PHOTONS and are generally found as components of the PHOTOSYSTEM I PROTEIN COMPLEX or the PHOTOSYSTEM II PROTEIN COMPLEX.
An enzyme that catalyzes the conversion of 4-hydroxyphenylpyruvate plus oxygen to homogentisic acid and carbon dioxide. EC 1.13.11.27.
A species of GREEN ALGAE. Delicate, hairlike appendages arise from the flagellar surface in these organisms.
A phylum of oxygenic photosynthetic bacteria comprised of unicellular to multicellular bacteria possessing CHLOROPHYLL a and carrying out oxygenic PHOTOSYNTHESIS. Cyanobacteria are the only known organisms capable of fixing both CARBON DIOXIDE (in the presence of light) and NITROGEN. Cell morphology can include nitrogen-fixing heterocysts and/or resting cells called akinetes. Formerly called blue-green algae, cyanobacteria were traditionally treated as ALGAE.
Cytochromes f are found as components of the CYTOCHROME B6F COMPLEX. They play important role in the transfer of electrons from PHOTOSYSTEM I to PHOTOSYSTEM II.
A lipid-soluble benzoquinone which is involved in ELECTRON TRANSPORT in mitochondrial preparations. The compound occurs in the majority of aerobic organisms, from bacteria to higher plants and animals.
The absence of light.
A widely cultivated plant, native to Asia, having succulent, edible leaves eaten as a vegetable. (From American Heritage Dictionary, 1982)
A collective name for a group of closely related lipids that contain substitutions on the 2H-1-benzopyran-6-ol nucleus and a long hydrocarbon chain of isoprenoid units. They are antioxidants by virtue of the phenolic hydrogen. Tocopherols react with the most reactive form of oxygen and protect unsaturated fatty acids from oxidation.
The property of emitting radiation while being irradiated. The radiation emitted is usually of longer wavelength than that incident or absorbed, e.g., a substance can be irradiated with invisible radiation and emit visible light. X-ray fluorescence is used in diagnosis.
A flavoprotein that reversibly oxidizes NADPH to NADP and a reduced acceptor. EC 1.6.99.1.
A phylum of photosynthetic EUKARYOTA bearing double membrane-bound plastids containing chlorophyll a and b. They comprise the classical green algae, and represent over 7000 species that live in a variety of primarily aquatic habitats. Only about ten percent are marine species, most live in freshwater.
Self-replicating cytoplasmic organelles of plant and algal cells that contain pigments and may synthesize and accumulate various substances. PLASTID GENOMES are used in phylogenetic studies.
Expanded structures, usually green, of vascular plants, characteristically consisting of a bladelike expansion attached to a stem, and functioning as the principal organ of photosynthesis and transpiration. (American Heritage Dictionary, 2d ed)
A form-genus of unicellular CYANOBACTERIA in the order Chroococcales. None of the strains fix NITROGEN, there are no gas vacuoles, and sheath layers are never produced.
Cytochromes (electron-transporting proteins) with protoheme (HEME B) as the prosthetic group.
A class of compounds composed of repeating 5-carbon units of HEMITERPENES.
Multicellular, eukaryotic life forms of kingdom Plantae (sensu lato), comprising the VIRIDIPLANTAE; RHODOPHYTA; and GLAUCOPHYTA; all of which acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations.
Peroxidases that utilize ASCORBIC ACID as an electron donor to reduce HYDROGEN PEROXIDE to WATER. The reaction results in the production of monodehydroascorbic acid and DEHYDROASCORBIC ACID.
A flavoprotein and iron sulfur-containing oxidoreductase that catalyzes the oxidation of NADH to NAD. In eukaryotes the enzyme can be found as a component of mitochondrial electron transport complex I. Under experimental conditions the enzyme can use CYTOCHROME C GROUP as the reducing cofactor. The enzyme was formerly listed as EC 1.6.2.1.
Benzene rings which contain two ketone moieties in any position. They can be substituted in any position except at the ketone groups.
Pesticides used to destroy unwanted vegetation, especially various types of weeds, grasses (POACEAE), and woody plants. Some plants develop HERBICIDE RESISTANCE.
A plant genus of the family SOLANACEAE. Members contain NICOTINE and other biologically active chemicals; its dried leaves are used for SMOKING.
Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which VEGETABLE PROTEINS is available.
A family of 3,6-di(substituted-amino)-9-benzoate derivatives of xanthene that are used as dyes and as indicators for various metals; also used as fluorescent tracers in histochemistry.
A plant genus of the family POACEAE. The EDIBLE GRAIN, barley, is widely used as food.
A plant genus of the family BRASSICACEAE that contains ARABIDOPSIS PROTEINS and MADS DOMAIN PROTEINS. The species A. thaliana is used for experiments in classical plant genetics as well as molecular genetic studies in plant physiology, biochemistry, and development.
The general name for a group of fat-soluble pigments found in green, yellow, and leafy vegetables, and yellow fruits. They are aliphatic hydrocarbons consisting of a polyisoprene backbone.
A plant genus in the family ROSACEAE, order Rosales, subclass Rosidae. It is best known as a source of the edible fruit (apple) and is cultivated in temperate climates worldwide.

The Qo site of cytochrome b6f complexes controls the activation of the LHCII kinase. (1/211)

We created a Qo pocket mutant by site-directed mutagenesis of the chloroplast petD gene in Chlamydomonas reinhardtii. We mutated the conserved PEWY sequence in the EF loop of subunit IV into PWYE. The pwye mutant did not grow in phototrophic conditions although it assembled wild-type levels of cytochrome b6f complexes. We demonstrated a complete block in electron transfer through the cytochrome b6f complex and a loss of plastoquinol binding at Qo. The accumulation of cytochrome b6f complexes lacking affinity for plastoquinol enabled us to investigate the role of plastoquinol binding at Qo in the activation of the light-harvesting complex II (LHCII) kinase during state transitions. We detected no fluorescence quenching at room temperature in state II conditions relative to that in state I. The quantum yield spectrum of photosystem I charge separation in the two state conditions displayed a trough in the absorption region of the major chlorophyll a/b proteins, demonstrating that the cells remained locked in state I. 33Pi labeling of the phosphoproteins in vivo demonstrated that the antenna proteins remained poorly phosphorylated in both state conditions. Thus, the absence of state transitions in the pwye mutant demonstrates directly that plastoquinol binding in the Qo pocket is required for LHCII kinase activation.  (+info)

Type 2 NADH dehydrogenases in the cyanobacterium Synechocystis sp. strain PCC 6803 are involved in regulation rather than respiration. (2/211)

Analysis of the genome of Synechocystis sp. strain PCC 6803 reveals three open reading frames (slr0851, slr1743, and sll1484) that may code for type 2 NAD(P)H dehydrogenases (NDH-2). The sequence similarity between the translated open reading frames and NDH-2s from other organisms is low, generally not exceeding 30% identity. However, NAD(P)H and flavin adenine dinucleotide binding motifs are conserved in all three putative NDH-2s in Synechocystis sp. strain PCC 6803. The three open reading frames were cloned, and deletion constructs were made for each. An expression construct containing one of the three open reading frames, slr1743, was able to functionally complement an Escherichia coli mutant lacking both NDH-1s and NDH-2s. Therefore, slr0851, slr1743, and sll1484 have been designated ndbA, ndbB, and ndbC, respectively. Strains that lacked one or more of the ndb genes were created in wild-type and photosystem (PS) I-less backgrounds. Deletion of ndb genes led to small changes in photoautotrophic growth rates and respiratory activities. Electron transfer rates into the plastoquinone pool in thylakoids in darkness were consistent with the presence of a small amount of NDH-2 activity in thylakoids. No difference was observed between wild-type and the Ndb-less strains in the banding patterns seen on native gels when stained for either NADH or NADPH dehydrogenase activity, indicating that the Ndb proteins do not accumulate to high levels. A striking phenotype of the PS I-less background strains lacking one or more of the NDH-2s is that they were able to grow at high light intensities that were lethal to the control strain but they retained normal PS II activity. We suggest that the Ndb proteins in Synechocystis sp. strain PCC 6803 are redox sensors and that they play a regulatory role responding to the redox state of the plastoquinone pool.  (+info)

Lag phase of CO2-dependent O2 evolution by illuminated Anabaena variabilis cells. (3/211)

The steady-state rate of CO2-dependent O2 evolution by Anabaena variabilis cells in response to illumination was established after a lag phase. The lag phase was shortened (1) in cells incubated with glucose as an oxidizable substrate and (2) upon an increase in light intensity. The lag phase was absent during electron transfer from H2O to p-benzoquinone (in combination with ferricyanide) involving Photosystem II. A lag was observed during electron transfer from H2O to methyl viologen involving Photosystems II and I, but not for electron transfer from N,N,N',N'-tetramethyl-p-phenylenediamine (in combination with ascorbate) to methyl viologen involving only Photosystem I. The lag phases of the light-induced H2O --> CO2 and H2O --> methyl viologen electron transfer reactions showed the same temperature dependences at 10-30 degrees C. The lag was prevented by 3-(3,4-dichlorophenyl)-1,1-dimethylurea at concentrations that caused partial inhibition of photosynthetic O2 evolution. Retardation of cell respiration by a combination of CN- and benzylhydroxamate shortened the lag phase of the H2O --> methyl viologen electron transfer. It is concluded that the lag phase is associated with the electron transfer step between Photosystem II and Photosystem I common for the photosynthetic and respiratory chains and is due to the stimulation of cell respiration during the initial period of illumination as a consequence of an increase in the reduced plastoquinone pool and to subsequent retardation of respiration resulting from the transition of the electron transfer chain to the competitive pathway involving Photosystem I.  (+info)

The phosphoenolpyruvate/phosphate translocator is required for phenolic metabolism, palisade cell development, and plastid-dependent nuclear gene expression. (4/211)

The Arabidopsis chlorophyll a/b binding protein (CAB) gene underexpressed 1 (cue1) mutant underexpresses light-regulated nuclear genes encoding chloroplast-localized proteins. cue1 also exhibits mesophyll-specific chloroplast and cellular defects, resulting in reticulate leaves. Both the gene underexpression and the leaf cell morphology phenotypes are dependent on light intensity. In this study, we determine that CUE1 encodes the plastid inner envelope phosphoenolpyruvate/phosphate translocator (PPT) and define amino acid residues that are critical for translocator function. The biosynthesis of aromatics is compromised in cue1, and the reticulate phenotype can be rescued by feeding aromatic amino acids. Determining that CUE1 encodes PPT indicates the in vivo role of the translocator in metabolic partitioning and reveals a mesophyll cell-specific requirement for the translocator in Arabidopsis leaves. The nuclear gene expression defects in cue1 suggest that a light intensity-dependent interorganellar signal is modulated through metabolites dependent on a plastid supply of phosphoenolpyruvate.  (+info)

Catalytic properties of an expressed and purified higher plant type zeta-carotene desaturase from Capsicum annuum. (5/211)

The zeta-carotene desaturase from Capsicum annuum (EC 1.14.99.-) was expressed in Escherichia coli, purified and characterized biochemically. The enzyme acts as a monomer with lipophilic quinones as cofactors. Km values for the substrate zeta-carotene or the intermediate neurosporene in the two-step desaturation reaction are almost identical. Product analysis showed that different lycopene isomers are formed, including substantial amounts of the all-trans form, together with 7,7',9,9'-tetracis prolycopene via the corresponding neurosporene isomers. The application of different geometric isomers as substrates revealed that the zeta-carotene desaturase has no preference for certain isomers and that the nature of the isomers formed during catalysis depends strictly on the isomeric composition of the substrate.  (+info)

Chlororespiration and poising of cyclic electron transport. Plastoquinone as electron transporter between thylakoid NADH dehydrogenase and peroxidase. (6/211)

Polypeptides encoded by plastid ndh genes form a complex (Ndh) which could reduce plastoquinone with NADH. Through a terminal oxidase, reduced plastoquinone would be oxidized in chlororespiration. However, isolated Ndh complex has low activity with plastoquinone and no terminal oxidase has been found in chloroplasts, thus the function of Ndh complex is unknown. Alternatively, thylakoid hydroquinone peroxidase could oxidize reduced plastoquinone with H(2)O(2). By immunoaffinity chromatography, we have purified the plastid Ndh complex of barley (Hordeum vulgare L.) to investigate the electron donor and acceptor specificity. A detergent-containing system was reconstructed with thylakoid Ndh complex and peroxidase which oxidized NADH with H(2)O(2) in a plastoquinone-dependent process. This system and the increases of thylakoid Ndh complex and peroxidase activities under photooxidative stress suggest that the chlororespiratory process consists of the sequence of reactions catalyzed by Ndh complex, peroxidase (acting on reduced plastoquinone), superoxide dismutase, and the non-enzymic one-electron transfer from reduced iron-sulfur protein (FeSP) to O(2). When FeSP is a component of cytochrome b(6).f complex or of the same Ndh complex, O(2) may be reduced with NADH, without requirement of light. Chlororespiration consumes reactive species of oxygen and, eventually, may decrease their production by lowering O(2) concentration in chloroplasts. The common plastoquinone pool with photosynthetic electron transport suggests that chlororespiratory reactions may poise reduced and oxidized forms of the intermediates of cyclic electron transport under highly fluctuating light intensities.  (+info)

Subcellular localization of plastoquinone and ubiquinone synthesis in spinach cells. (7/211)

In vivo labeling of spinach etiolated leaves with [(3)H]mevalonate followed by rapid cell fractionation procedure showed that ER-Golgi membranes are involved in transport of plastoquinone (PQ) and ubiquinone (UQ) to plastids and mitochondria, respectively. Translocation of these lipids was inhibited by agents which affect protein and lipid intracellular transport causing structural and functional disintegration of the ER-Golgi system (monensin, brefeldin) and interfere with mitochondrial energy conservation (carbonyl cyanide m-chlorophenylhydrazone), but was not affected by colchicine which influences the organization of the cytoskeletal network. Colchicine treatment resulted in marked stimulation of PQ and UQ synthesis. Results of experiments with pre-exposure of etiolated seedlings to light suggest that translocation processes are dependent on the plastid developmental state and their capacity as acceptors of PQ. Thus, the experiments indicate that biosynthesis and transport of PQ and UQ involve multiple cellular compartments and that kinetics of the transport process is dependent on the actual physiological conditions.  (+info)

GTP enhances the degradation of the photosystem II D1 protein irrespective of its conformational heterogeneity at the Q(B) site. (8/211)

The light exposure history and/or binding of different herbicides at the Q(B) site may induce heterogeneity of photosystem II acceptor side conformation that affects D1 protein degradation under photoinhibitory conditions. GTP was recently found to stimulate the D1 protein degradation of photoinactivated photosystem II (Spetea, C. , Hundal, T., Lohmann, F., and Andersson, B. (1999) Proc. Natl. Acad. Sci. U. S. A. 96, 6547-6552). Here we report that GTP enhances the cleavage of the D1 protein D-E loop following exposure of thylakoid membranes to either high light, low light, or repetitive single turnover flashes but not to trypsin. GTP does not stimulate D1 protein degradation in the presence of herbicides known to affect the accessibility of the cleavage site to proteolysis. However, GTP stimulates degradation that can be induced even in darkness in some photosystem II conformers following binding of the PNO8 herbicide (Nakajima, Y., Yoshida, S., Inoue, Y., Yoneyama, K., and Ono, T. (1995) Biochim. Biophys. Acta 1230, 38-44). Both the PNO8- and the light-induced primary cleavage of the D1 protein occur in the grana membrane domains. The subsequent migration of photosytem II containing the D1 protein fragments to the stroma domains for secondary proteolysis is light-activated. We conclude that the GTP effect is not confined to a specific photoinactivation pathway nor to the conformational state of the photosystem II acceptor side. Consequently, GTP does not interact with the site of D1 protein cleavage but rather enhances the activity of the endogenous proteolytic system.  (+info)

Plastoquinone is a lipid-soluble electron carrier in the photosynthetic electron transport chain located in the thylakoid membrane of chloroplasts. It plays a crucial role in both the light-dependent reactions of photosynthesis and cyclic photophosphorylation.

In more detail, plastoquinone exists in an oxidized (PQ) and reduced form (PQH2). In its oxidized state, it accepts electrons from cytochrome b6f complex during the transfer of electrons from photosystem II to photosystem I. Once plastoquinone accepts two electrons and two protons, it converts into its reduced form, plastoquinol (PQH2). Plastoquinol then donates the electrons to the cytochrome b6f complex, which in turn passes them on to the next carrier in the electron transport chain.

Plastoquinone is a member of the quinone family and is synthesized via the methylerythritol 4-phosphate (MEP) pathway, also known as the non-mevalonate pathway.

Dibromothymoquinone is not a medical term, but a chemical compound with the formula C10H8Br2O2. It is an orange crystalline powder that is slightly soluble in water and more soluble in organic solvents. Dibromothymoquinone is used as a intermediate in the synthesis of various pharmaceuticals and other chemical products.

It does not have any specific medical use or indication, but it may have some biological activities that could be explored for potential therapeutic applications. For example, some studies suggest that dibromothymoquinone has anticancer, anti-inflammatory, and antioxidant properties, although more research is needed to confirm these findings and determine the safety and efficacy of this compound in humans.

Therefore, it is important to consult with a healthcare professional or a chemist for more information about dibromothymoquinone and its potential uses or risks.

Diuron is a pesticide and herbicide that is used to control weeds in various settings, such as agriculture, landscaping, and forestry. Its chemical name is 3-(3,4-dichlorophenyl)-1,1-dimethylurea. Diuron works by inhibiting photosynthesis in plants, which prevents them from growing and eventually kills them.

While diuron is effective at controlling weeds, it can also have harmful effects on non-target organisms, including aquatic life and pollinators. Additionally, there are concerns about the potential for diuron to contaminate water sources and pose risks to human health. As a result, its use is regulated in many countries, and there are restrictions on how it can be applied and disposed of.

It's worth noting that Diuron is not a medical term or a drug used for treating any medical condition in humans or animals.

Photosystem II Protein Complex is a crucial component of the photosynthetic apparatus in plants, algae, and cyanobacteria. It is a multi-subunit protein complex located in the thylakoid membrane of the chloroplasts. Photosystem II plays a vital role in light-dependent reactions of photosynthesis, where it absorbs sunlight and uses its energy to drive the oxidation of water molecules into oxygen, electrons, and protons.

The protein complex consists of several subunits, including the D1 and D2 proteins, which form the reaction center, and several antenna proteins that capture light energy and transfer it to the reaction center. Photosystem II also contains various cofactors, such as pigments (chlorophylls and carotenoids), redox-active metal ions (manganese and calcium), and quinones, which facilitate the charge separation and electron transfer processes during photosynthesis.

Photosystem II Protein Complex is responsible for the initial charge separation event in photosynthesis, which sets off a series of redox reactions that ultimately lead to the reduction of NADP+ to NADPH and the synthesis of ATP, providing energy for the carbon fixation reactions in the Calvin cycle. Additionally, Photosystem II Protein Complex is involved in oxygen evolution, contributing to the Earth's atmosphere's oxygen levels and making it an essential component of global carbon fixation and oxygen production.

Thylakoids are membrane-bound structures located in the chloroplasts of plant cells and some protists. They are the site of the light-dependent reactions of photosynthesis, where light energy is converted into chemical energy in the form of ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate). Thylakoids have a characteristic stacked or disc-like structure, called grana, and are interconnected by unstacked regions called stroma lamellae. The arrangement of thylakoids in grana increases the surface area for absorption of light energy, allowing for more efficient photosynthesis.

Photosynthesis is not strictly a medical term, but it is a fundamental biological process with significant implications for medicine, particularly in understanding energy production in cells and the role of oxygen in sustaining life. Here's a general biological definition:

Photosynthesis is a process by which plants, algae, and some bacteria convert light energy, usually from the sun, into chemical energy in the form of organic compounds, such as glucose (or sugar), using water and carbon dioxide. This process primarily takes place in the chloroplasts of plant cells, specifically in structures called thylakoids. The overall reaction can be summarized as:

6 CO2 + 6 H2O + light energy → C6H12O6 + 6 O2

In this equation, carbon dioxide (CO2) and water (H2O) are the reactants, while glucose (C6H12O6) and oxygen (O2) are the products. Photosynthesis has two main stages: the light-dependent reactions and the light-independent reactions (Calvin cycle). The light-dependent reactions occur in the thylakoid membrane and involve the conversion of light energy into ATP and NADPH, which are used to power the Calvin cycle. The Calvin cycle takes place in the stroma of chloroplasts and involves the synthesis of glucose from CO2 and water using the ATP and NADPH generated during the light-dependent reactions.

Understanding photosynthesis is crucial for understanding various biological processes, including cellular respiration, plant metabolism, and the global carbon cycle. Additionally, research into artificial photosynthesis has potential applications in renewable energy production and environmental remediation.

The cytochrome b6f complex is a protein complex in the thylakoid membrane of the chloroplasts in plants, algae, and cyanobacteria. It plays a crucial role in the light-dependent reactions of photosynthesis by facilitating the transfer of electrons from photosystem II to photosystem I.

The complex is composed of four subunits: cytochrome b6, subunit IV, and two Rieske iron-sulfur proteins. Cytochrome b6 is a heme protein that contains two heme groups, while subunit IV helps anchor the complex in the thylakoid membrane. The Rieske iron-sulfur proteins contain a 2Fe-2S cluster and are responsible for transferring electrons between cytochrome b6 and plastoquinone, a mobile electron carrier.

The cytochrome b6f complex functions in the Q-cycle, which is a mechanism that increases the efficiency of electron transfer and generates a proton gradient across the thylakoid membrane. This proton gradient drives the synthesis of ATP, an essential energy currency for the cell. Overall, the cytochrome b6f complex is a vital component of the photosynthetic machinery, enabling the conversion of light energy into chemical energy in the form of ATP and NADPH.

Quinones are a class of organic compounds that contain a fully conjugated diketone structure. This structure consists of two carbonyl groups (C=O) separated by a double bond (C=C). Quinones can be found in various biological systems and synthetic compounds. They play important roles in many biochemical processes, such as electron transport chains and redox reactions. Some quinones are also known for their antimicrobial and anticancer properties. However, some quinones can be toxic or mutagenic at high concentrations.

Chlorophyll is a green pigment found in the chloroplasts of photosynthetic plants, algae, and some bacteria. It plays an essential role in light-dependent reactions of photosynthesis by absorbing light energy, primarily from the blue and red parts of the electromagnetic spectrum, and converting it into chemical energy to fuel the synthesis of carbohydrates from carbon dioxide and water. The structure of chlorophyll includes a porphyrin ring, which binds a central magnesium ion, and a long phytol tail. There are several types of chlorophyll, including chlorophyll a and chlorophyll b, which have distinct absorption spectra and slightly different structures. Chlorophyll is crucial for the process of photosynthesis, enabling the conversion of sunlight into chemical energy and the release of oxygen as a byproduct.

Chloroplasts are specialized organelles found in the cells of green plants, algae, and some protists. They are responsible for carrying out photosynthesis, which is the process by which these organisms convert light energy from the sun into chemical energy in the form of organic compounds, such as glucose.

Chloroplasts contain the pigment chlorophyll, which absorbs light energy from the sun. They also contain a system of membranes and enzymes that convert carbon dioxide and water into glucose and oxygen through a series of chemical reactions known as the Calvin cycle. This process not only provides energy for the organism but also releases oxygen as a byproduct, which is essential for the survival of most life forms on Earth.

Chloroplasts are believed to have originated from ancient cyanobacteria that were engulfed by early eukaryotic cells and eventually became integrated into their host's cellular machinery through a process called endosymbiosis. Over time, chloroplasts evolved to become an essential component of plant and algal cells, contributing to their ability to carry out photosynthesis and thrive in a wide range of environments.

The Electron Transport Chain (ETC) is a series of complexes in the inner mitochondrial membrane that are involved in the process of cellular respiration. It is the final pathway for electrons derived from the oxidation of nutrients such as glucose, fatty acids, and amino acids to be transferred to molecular oxygen. This transfer of electrons drives the generation of a proton gradient across the inner mitochondrial membrane, which is then used by ATP synthase to produce ATP, the main energy currency of the cell.

The electron transport chain consists of four complexes (I-IV) and two mobile electron carriers (ubiquinone and cytochrome c). Electrons from NADH and FADH2 are transferred to Complex I and Complex II respectively, which then pass them along to ubiquinone. Ubiquinone then transfers the electrons to Complex III, which passes them on to cytochrome c. Finally, cytochrome c transfers the electrons to Complex IV, where they combine with oxygen and protons to form water.

The transfer of electrons through the ETC is accompanied by the pumping of protons from the mitochondrial matrix to the intermembrane space, creating a proton gradient. The flow of protons back across the inner membrane through ATP synthase drives the synthesis of ATP from ADP and inorganic phosphate.

Overall, the electron transport chain is a crucial process for generating energy in the form of ATP in the cell, and it plays a key role in many metabolic pathways.

Photosystem I Protein Complex, also known as PsaA/B-Protein or Photosystem I reaction center, is a large protein complex found in the thylakoid membrane of plant chloroplasts and cyanobacteria. It plays a crucial role in light-dependent reactions of photosynthesis, where it absorbs light energy and converts it into chemical energy in the form of NADPH.

The complex is composed of several subunits, including PsaA and PsaB, which are the core components that bind to chlorophyll a and bacteriochlorophyll a pigments. These pigments absorb light energy and transfer it to the reaction center, where it is used to drive the electron transport chain and generate a proton gradient across the membrane. This gradient is then used to produce ATP, which provides energy for the carbon fixation reactions in photosynthesis.

Photosystem I Protein Complex is also involved in cyclic electron flow, where electrons are recycled within the complex to generate additional ATP without producing NADPH. This process helps regulate the balance between ATP and NADPH production in the chloroplast and optimizes the efficiency of photosynthesis.

Photosynthetic Reaction Center (RC) Complex Proteins are specialized protein-pigment structures that play a crucial role in the primary process of light-driven electron transport during photosynthesis. They are present in the thylakoid membranes of cyanobacteria, algae, and higher plants.

The Photosynthetic Reaction Center Complex Proteins are composed of two major components: the light-harvesting complex (LHC) and the reaction center (RC). The LHC contains antenna pigments like chlorophylls and carotenoids that absorb sunlight and transfer the excitation energy to the RC. The RC is a multi-subunit protein complex containing cofactors such as bacteriochlorophyll, pheophytin, quinones, and iron-sulfur clusters.

When a photon of light is absorbed by the antenna pigments in the LHC, the energy is transferred to the RC, where it initiates a charge separation event. This results in the transfer of an electron from a donor molecule to an acceptor molecule, creating a flow of electrical charge and generating a transmembrane electrochemical gradient. The energy stored in this gradient is then used to synthesize ATP and reduce NADP+, which are essential for carbon fixation and other metabolic processes in the cell.

In summary, Photosynthetic Reaction Center Complex Proteins are specialized protein structures involved in capturing light energy and converting it into chemical energy during photosynthesis, ultimately driving the synthesis of ATP and NADPH for use in carbon fixation and other metabolic processes.

In the context of medical terminology, "light" doesn't have a specific or standardized definition on its own. However, it can be used in various medical terms and phrases. For example, it could refer to:

1. Visible light: The range of electromagnetic radiation that can be detected by the human eye, typically between wavelengths of 400-700 nanometers. This is relevant in fields such as ophthalmology and optometry.
2. Therapeutic use of light: In some therapies, light is used to treat certain conditions. An example is phototherapy, which uses various wavelengths of ultraviolet (UV) or visible light for conditions like newborn jaundice, skin disorders, or seasonal affective disorder.
3. Light anesthesia: A state of reduced consciousness in which the patient remains responsive to verbal commands and physical stimulation. This is different from general anesthesia where the patient is completely unconscious.
4. Pain relief using light: Certain devices like transcutaneous electrical nerve stimulation (TENS) units have a 'light' setting, indicating lower intensity or frequency of electrical impulses used for pain management.

Without more context, it's hard to provide a precise medical definition of 'light'.

'Euglena' is a genus of unicellular flagellate protists that are typically characterized by their oval-shaped bodies, long whip-like tail (flagellum), and eyespot (stigma) which helps them to move towards light. They are commonly found in freshwater environments and can also be found in soil and brackish water. Some species of Euglena have the ability to photosynthesize, while others obtain their nutrition through heterotrophy (consuming other organisms or organic matter). The term 'Euglena' is derived from the Greek word 'euglenes', which means "well-shaped" or "true-eyed". Medical professionals and researchers may study Euglena as part of broader research into protists, microbiology, or ecology.

Oxidation-Reduction (redox) reactions are a type of chemical reaction involving a transfer of electrons between two species. The substance that loses electrons in the reaction is oxidized, and the substance that gains electrons is reduced. Oxidation and reduction always occur together in a redox reaction, hence the term "oxidation-reduction."

In biological systems, redox reactions play a crucial role in many cellular processes, including energy production, metabolism, and signaling. The transfer of electrons in these reactions is often facilitated by specialized molecules called electron carriers, such as nicotinamide adenine dinucleotide (NAD+/NADH) and flavin adenine dinucleotide (FAD/FADH2).

The oxidation state of an element in a compound is a measure of the number of electrons that have been gained or lost relative to its neutral state. In redox reactions, the oxidation state of one or more elements changes as they gain or lose electrons. The substance that is oxidized has a higher oxidation state, while the substance that is reduced has a lower oxidation state.

Overall, oxidation-reduction reactions are fundamental to the functioning of living organisms and are involved in many important biological processes.

Vitamin K1, also known as phylloquinone, is a type of fat-soluble vitamin K. It is the primary form of Vitamin K found in plants, particularly in green leafy vegetables such as kale, spinach, and collard greens. Vitamin K1 plays a crucial role in blood clotting and helps to prevent excessive bleeding by assisting in the production of several proteins involved in this process. It is also essential for maintaining healthy bones by aiding in the regulation of calcium deposition in bone tissue. A deficiency in Vitamin K1 can lead to bleeding disorders and, in some cases, osteoporosis.

Light-harvesting protein complexes are specialized structures in photosynthetic organisms, such as plants, algae, and some bacteria, that capture and transfer light energy to the reaction centers where the initial chemical reactions of photosynthesis occur. These complexes consist of proteins and pigments (primarily chlorophylls and carotenoids) arranged in a way that allows them to absorb light most efficiently. The absorbed light energy is then converted into electrical charges, which are transferred to the reaction centers for further chemical reactions leading to the production of organic compounds and oxygen. The light-harvesting protein complexes play a crucial role in initiating the process of photosynthesis and optimizing its efficiency by capturing and distributing light energy.

4-Hydroxyphenylpyruvate dioxygenase (HPPD) is an enzyme that is involved in the catabolism of aromatic amino acids such as tyrosine. The gene for HPPD is located on human chromosome 12q24.11.

The HPPD enzyme catalyzes the conversion of 4-hydroxyphenylpyruvate to homogentisate, which is then further metabolized in the catabolic pathway leading to fumarate and acetoacetate. Deficiencies in HPPD activity have been associated with certain genetic disorders such as tyrosinemia type III, which can result in neurological symptoms and developmental delays.

In addition to its role in normal metabolism, HPPD has also been identified as a target for herbicides that inhibit the enzyme's activity, leading to the accumulation of 4-hydroxyphenylpyruvate and other toxic intermediates that can disrupt plant growth and development.

Chlamydomonas reinhardtii is a species of single-celled, freshwater green algae. It is commonly used as a model organism in scientific research due to its simple unicellular structure and the ease with which it can be genetically manipulated. C. reinhardtii has a single, large chloroplast that contains both photosynthetic pigments and a nucleomorph, a remnant of a secondary endosymbiotic event where another alga was engulfed by an ancestral eukaryote. This species is capable of both phototactic and photophobic responses, allowing it to move towards or away from light sources. Additionally, C. reinhardtii has two flagella for locomotion, making it a popular subject for ciliary and flagellar research. It undergoes closed mitosis within its single, diploid nucleus, which is surrounded by a cell wall composed of glycoproteins. The genome of C. reinhardtii has been fully sequenced, providing valuable insights into the molecular mechanisms underlying photosynthesis, flagellar assembly, and other fundamental biological processes.

Cyanobacteria, also known as blue-green algae, are a type of bacteria that obtain their energy through photosynthesis, similar to plants. They can produce oxygen and contain chlorophyll a, which gives them a greenish color. Some species of cyanobacteria can produce toxins that can be harmful to humans and animals if ingested or inhaled. They are found in various aquatic environments such as freshwater lakes, ponds, and oceans, as well as in damp soil and on rocks. Cyanobacteria are important contributors to the Earth's oxygen-rich atmosphere and play a significant role in the global carbon cycle.

Cytochrome f is a type of cytochrome protein that contains heme as a cofactor and plays a role in the electron transport chain during photosynthesis. It is specifically located in the cytochrome b6f complex, which is found in the thylakoid membrane of chloroplasts in plants and algae.

Cytochrome f functions as a ubiquinol-plastoquinone oxidoreductase, accepting electrons from ubiquinol and transferring them to plastoquinone. This electron transfer process is an essential step in the generation of a proton gradient across the thylakoid membrane, which drives the synthesis of ATP during photosynthesis.

Deficiency or mutation in cytochrome f can lead to impaired photosynthetic efficiency and reduced growth in plants.

Ubiquinone, also known as coenzyme Q10 (CoQ10), is a lipid-soluble benzoquinone that plays a crucial role in the mitochondrial electron transport chain as an essential component of Complexes I, II, and III. It functions as an electron carrier, assisting in the transfer of electrons from reduced nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FADH2) to molecular oxygen during oxidative phosphorylation, thereby contributing to the generation of adenosine triphosphate (ATP), the primary energy currency of the cell.

Additionally, ubiquinone acts as a potent antioxidant in both membranes and lipoproteins, protecting against lipid peroxidation and oxidative damage to proteins and DNA. Its antioxidant properties stem from its ability to donate electrons and regenerate other antioxidants like vitamin E. Ubiquinone is synthesized endogenously in all human cells, with the highest concentrations found in tissues with high energy demands, such as the heart, liver, kidneys, and skeletal muscles.

Deficiency in ubiquinone can result from genetic disorders, aging, or certain medications (such as statins), leading to impaired mitochondrial function and increased oxidative stress. Supplementation with ubiquinone has been explored as a potential therapeutic strategy for various conditions associated with mitochondrial dysfunction and oxidative stress, including cardiovascular diseases, neurodegenerative disorders, and cancer.

I am not aware of a medical definition for the term "darkness." In general, darkness refers to the absence of light. It is not a term that is commonly used in the medical field, and it does not have a specific clinical meaning. If you have a question about a specific medical term or concept, I would be happy to try to help you understand it.

"Spinacia oleracea" is the scientific name for a plant species, not a medical term. It is commonly known as spinach, a leafy green vegetable. While spinach has many health benefits and is often recommended as part of a balanced diet, it does not have a specific medical definition.

Spinach is rich in various nutrients such as iron, calcium, vitamin A, vitamin C, and folic acid. It can contribute to overall health, support immune function, and provide antioxidant benefits. However, it is important to note that 'Spinacia oleracea' itself does not have a medical definition.

Tocopherols are a group of fat-soluble compounds that occur naturally in vegetable oils, nuts, and some fruits and vegetables. They are known for their antioxidant properties and are often referred to as "vitamin E." The term "tocopherol" is derived from the Greek words "tokos," meaning childbirth, and "pherein," meaning to bear, reflecting the historical observation that consumption of certain foods during pregnancy seemed to prevent fetal death and spontaneous abortion.

There are four major forms of tocopherols: alpha, beta, gamma, and delta. Alpha-tocopherol is the most biologically active form and is the one most commonly found in supplements. Tocopherols play a crucial role in protecting cell membranes from damage caused by free radicals, which are unstable molecules that can harm cells and contribute to aging and diseases such as cancer and heart disease. They also help to maintain the integrity of the skin and mucous membranes, support immune function, and have been shown to have anti-inflammatory effects.

Fluorescence is not a medical term per se, but it is widely used in the medical field, particularly in diagnostic tests, medical devices, and research. Fluorescence is a physical phenomenon where a substance absorbs light at a specific wavelength and then emits light at a longer wavelength. This process, often referred to as fluorescing, results in the emission of visible light that can be detected and measured.

In medical terms, fluorescence is used in various applications such as:

1. In-vivo imaging: Fluorescent dyes or probes are introduced into the body to highlight specific structures, cells, or molecules during imaging procedures. This technique can help doctors detect and diagnose diseases such as cancer, inflammation, or infection.
2. Microscopy: Fluorescence microscopy is a powerful tool for visualizing biological samples at the cellular and molecular level. By labeling specific proteins, nucleic acids, or other molecules with fluorescent dyes, researchers can observe their distribution, interactions, and dynamics within cells and tissues.
3. Surgical guidance: Fluorescence-guided surgery is a technique where surgeons use fluorescent markers to identify critical structures such as blood vessels, nerves, or tumors during surgical procedures. This helps ensure precise and safe surgical interventions.
4. Diagnostic tests: Fluorescence-based assays are used in various diagnostic tests to detect and quantify specific biomarkers or analytes. These assays can be performed using techniques such as enzyme-linked immunosorbent assay (ELISA), polymerase chain reaction (PCR), or flow cytometry.

In summary, fluorescence is a physical process where a substance absorbs and emits light at different wavelengths. In the medical field, this phenomenon is harnessed for various applications such as in-vivo imaging, microscopy, surgical guidance, and diagnostic tests.

NADPH Dehydrogenase (also known as Nicotinamide Adenine Dinucleotide Phosphate Hydrogen Dehydrogenase) is an enzyme that plays a crucial role in the electron transport chain within the mitochondria of cells. It catalyzes the oxidation of NADPH to NADP+, which is a vital step in the process of cellular respiration where energy is produced in the form of ATP (Adenosine Triphosphate).

There are multiple forms of this enzyme, including both membrane-bound and soluble varieties. The membrane-bound NADPH Dehydrogenase is a complex I protein found in the inner mitochondrial membrane, while the soluble form is located in the cytosol.

Mutations in genes encoding for this enzyme can lead to various medical conditions, such as mitochondrial disorders and neurological diseases.

Chlorophyta is a division of green algae, also known as green plants. This group includes a wide variety of simple, aquatic organisms that contain chlorophylls a and b, which gives them their characteristic green color. They are a diverse group, ranging from unicellular forms to complex multicellular seaweeds. Chlorophyta is a large and varied division with approximately 7,00

Plastids are membrane-bound organelles found in the cells of plants and algae. They are responsible for various cellular functions, including photosynthesis, storage of starch, lipids, and proteins, and the production of pigments that give plants their color. The most common types of plastids are chloroplasts (which contain chlorophyll and are involved in photosynthesis), chromoplasts (which contain pigments such as carotenoids and are responsible for the yellow, orange, and red colors of fruits and flowers), and leucoplasts (which do not contain pigments and serve mainly as storage organelles). Plastids have their own DNA and can replicate themselves within the cell.

I believe there may be a slight misunderstanding in your question. "Plant leaves" are not a medical term, but rather a general biological term referring to a specific organ found in plants.

Leaves are organs that are typically flat and broad, and they are the primary site of photosynthesis in most plants. They are usually green due to the presence of chlorophyll, which is essential for capturing sunlight and converting it into chemical energy through photosynthesis.

While leaves do not have a direct medical definition, understanding their structure and function can be important in various medical fields, such as pharmacognosy (the study of medicinal plants) or environmental health. For example, certain plant leaves may contain bioactive compounds that have therapeutic potential, while others may produce allergens or toxins that can impact human health.

I'm sorry for any confusion, but "Synechocystis" is not a medical term. It is actually a genus of cyanobacteria (also known as blue-green algae), which are gram-negative bacteria capable of photosynthesis. The most studied species, Synechocystis sp. PCC 6803, is often used as a model organism in research related to photosynthesis, carbon metabolism, and bioenergy.

If you have any medical terms or concepts that you would like me to define or explain, please let me know!

Cytochrome b is a type of cytochrome, which is a class of proteins that contain heme as a cofactor and are involved in electron transfer. Cytochromes are classified based on the type of heme they contain and their absorption spectra.

The cytochrome b group includes several subfamilies of cytochromes, including cytochrome b5, cytochrome b2, and cytochrome bc1 (also known as complex III). These cytochromes are involved in various biological processes, such as fatty acid desaturation, steroid metabolism, and the electron transport chain.

The electron transport chain is a series of protein complexes in the inner mitochondrial membrane that generates most of the ATP (adenosine triphosphate) required for cellular energy production. Cytochrome bc1 is a key component of the electron transport chain, where it functions as a dimer and catalyzes the transfer of electrons from ubiquinol to cytochrome c while simultaneously pumping protons across the membrane. This creates an electrochemical gradient that drives ATP synthesis.

Deficiencies or mutations in cytochrome b genes can lead to various diseases, such as mitochondrial disorders and cancer.

Terpenes are a large and diverse class of organic compounds produced by a variety of plants, including cannabis. They are responsible for the distinctive aromas and flavors found in different strains of cannabis. Terpenes have been found to have various therapeutic benefits, such as anti-inflammatory, analgesic, and antimicrobial properties. Some terpenes may also enhance the psychoactive effects of THC, the main psychoactive compound in cannabis. It's important to note that more research is needed to fully understand the potential medical benefits and risks associated with terpenes.

I apologize for any confusion, but "plants" is not a term that has a medical definition. The term "plants" refers to a large and diverse group of organisms that obtain their energy through photosynthesis, which is the process of converting sunlight into chemical energy. Plants are typically characterized by having cells with cell walls containing cellulose, chloroplasts containing the pigment chlorophyll, and the ability to synthesize their own food through photosynthesis.

In a medical or biological context, you might be thinking of "plant-based" or "phytomedicine," which refer to the use of plants or plant extracts as a form of medicine or treatment. Phytomedicines have been used for thousands of years in many traditional systems of medicine, and some plant-derived compounds have been found to have therapeutic benefits in modern medicine as well. However, "plants" itself does not have a medical definition.

Ascorbate peroxidases (AHPX) are a group of enzymes that use ascorbic acid (vitamin C) as a reducing cofactor to catalyze the conversion of hydrogen peroxide (H2O2) into water (H2O) and oxygen (O2). This reaction helps protect cells from oxidative damage caused by the accumulation of H2O2, a byproduct of various metabolic processes. Ascorbate peroxidases are primarily found in plants, algae, and cyanobacteria, where they play a crucial role in the detoxification of reactive oxygen species generated during photosynthesis.

NADH dehydrogenase, also known as Complex I, is an enzyme complex in the electron transport chain located in the inner mitochondrial membrane. It catalyzes the oxidation of NADH to NAD+ and the reduction of coenzyme Q to ubiquinol, playing a crucial role in cellular respiration and energy production. The reaction involves the transfer of electrons from NADH to coenzyme Q, which contributes to the generation of a proton gradient across the membrane, ultimately leading to ATP synthesis. Defects in NADH dehydrogenase can result in various mitochondrial diseases and disorders.

Benzoquinones are a type of chemical compound that contain a benzene ring (a cyclic arrangement of six carbon atoms) with two ketone functional groups (-C=O) in the 1,4-positions. They exist in two stable forms, namely ortho-benzoquinone and para-benzoquinone, depending on the orientation of the ketone groups relative to each other.

Benzoquinones are important intermediates in various biological processes and are also used in industrial applications such as dyes, pigments, and pharmaceuticals. They can be produced synthetically or obtained naturally from certain plants and microorganisms.

In the medical field, benzoquinones have been studied for their potential therapeutic effects, particularly in the treatment of cancer and infectious diseases. However, they are also known to exhibit toxicity and may cause adverse reactions in some individuals. Therefore, further research is needed to fully understand their mechanisms of action and potential risks before they can be safely used as drugs or therapies.

Herbicides are a type of pesticide used to control or kill unwanted plants, also known as weeds. They work by interfering with the growth processes of the plant, such as inhibiting photosynthesis, disrupting cell division, or preventing the plant from producing certain essential proteins.

Herbicides can be classified based on their mode of action, chemical composition, and the timing of their application. Some herbicides are selective, meaning they target specific types of weeds while leaving crops unharmed, while others are non-selective and will kill any plant they come into contact with.

It's important to use herbicides responsibly and according to the manufacturer's instructions, as they can have negative impacts on the environment and human health if not used properly.

Tobacco is not a medical term, but it refers to the leaves of the plant Nicotiana tabacum that are dried and fermented before being used in a variety of ways. Medically speaking, tobacco is often referred to in the context of its health effects. According to the World Health Organization (WHO), "tobacco" can also refer to any product prepared from the leaf of the tobacco plant for smoking, sucking, chewing or snuffing.

Tobacco use is a major risk factor for a number of diseases, including cancer, heart disease, stroke, lung disease, and various other medical conditions. The smoke produced by burning tobacco contains thousands of chemicals, many of which are toxic and can cause serious health problems. Nicotine, one of the primary active constituents in tobacco, is highly addictive and can lead to dependence.

"Plant proteins" refer to the proteins that are derived from plant sources. These can include proteins from legumes such as beans, lentils, and peas, as well as proteins from grains like wheat, rice, and corn. Other sources of plant proteins include nuts, seeds, and vegetables.

Plant proteins are made up of individual amino acids, which are the building blocks of protein. While animal-based proteins typically contain all of the essential amino acids that the body needs to function properly, many plant-based proteins may be lacking in one or more of these essential amino acids. However, by consuming a variety of plant-based foods throughout the day, it is possible to get all of the essential amino acids that the body needs from plant sources alone.

Plant proteins are often lower in calories and saturated fat than animal proteins, making them a popular choice for those following a vegetarian or vegan diet, as well as those looking to maintain a healthy weight or reduce their risk of chronic diseases such as heart disease and cancer. Additionally, plant proteins have been shown to have a number of health benefits, including improving gut health, reducing inflammation, and supporting muscle growth and repair.

Rhodamines are not a medical term, but rather a class of chemical compounds that are commonly used as dyes and fluorescent tracers in various fields, including biology, chemistry, and material science. They absorb light at one wavelength and emit it at another, longer wavelength, which makes them useful for tracking and visualizing processes in living cells and tissues.

In a medical context, rhodamines may be used as part of diagnostic tests or procedures, such as in fluorescence microscopy or flow cytometry, to label and detect specific cells or molecules of interest. However, they are not typically used as therapeutic agents themselves.

I'm sorry for any confusion, but "Hordeum" is not a medical term. It is actually the genus name for barley in botany. If you have any medical terms or concepts that you would like me to explain, please let me know!

'Arabidopsis' is a genus of small flowering plants that are part of the mustard family (Brassicaceae). The most commonly studied species within this genus is 'Arabidopsis thaliana', which is often used as a model organism in plant biology and genetics research. This plant is native to Eurasia and Africa, and it has a small genome that has been fully sequenced. It is known for its short life cycle, self-fertilization, and ease of growth, making it an ideal subject for studying various aspects of plant biology, including development, metabolism, and response to environmental stresses.

Carotenoids are a class of pigments that are naturally occurring in various plants and fruits. They are responsible for the vibrant colors of many vegetables and fruits, such as carrots, pumpkins, tomatoes, and leafy greens. There are over 600 different types of carotenoids, with beta-carotene, alpha-carotene, lycopene, lutein, and zeaxanthin being some of the most well-known.

Carotenoids have antioxidant properties, which means they can help protect the body's cells from damage caused by free radicals. Some carotenoids, such as beta-carotene, can be converted into vitamin A in the body, which is important for maintaining healthy vision, skin, and immune function. Other carotenoids, such as lycopene and lutein, have been studied for their potential role in preventing chronic diseases, including cancer and heart disease.

In addition to being found in plant-based foods, carotenoids can also be taken as dietary supplements. However, it is generally recommended to obtain nutrients from whole foods rather than supplements whenever possible, as food provides a variety of other beneficial compounds that work together to support health.

I'm sorry for any confusion, but "Malus" is not a medical term. It is a genus name in the plant kingdom, referring to the apple tree. If you have a different term or concept in mind, please provide it so I can give you an accurate definition or explanation.

Plastoquinone is found within photosystem II in two specific binding sites, known as QA and QB. The plastoquinone at QA, the ... The protonated QB then joins a pool of free plastoquinone molecules in the membrane of the thylakoid. The free plastoquinone ... dictionary.reference.com/browse/Plastoquinone Definition of plastoquinone Lambreva, Maya D.; Russo, Daniela; Polticelli, Fabio ... Plastoquinone is reduced when it accepts two electrons from photosystem II and two hydrogen cations (H+) from the stroma of the ...
The key difference between ubiquinone and plastoquinone is that ubiquinone is present in the inner membrane of mitochondria ... Plastoquinone A (PQ-A) or plastoquinone 09 (PQ-9) is the most common type of plastoquinone present in plants. This type is a 2 ... 3. What is Plastoquinone. 4. Similarities - Ubiquinone and Plastoquinone. 5. Ubiquinone vs Plastoquinone in Tabular Form. 6. ... What is Plastoquinone?. Plastoquinone is a type of prenylquinone that acts as an electron carrier in the electron transport ...
PCC 6803 results in plastoquinone-9 (PQ-9) occupying the A1 site and functioning in electron transfer from A1 to the FeS ... Recruitment of a foreign quinone into the A1 site of photosystem I: In vivo replacement of plastoquinone-9 by media- ... Recruitment of a foreign quinone into the A1 site of photosystem I: In vivo replacement of plastoquinone-9 by media- ... Recruitment of a foreign quinone into the A1 site of photosystem I : In vivo replacement of plastoquinone-9 by media- ...
Double reduction of plastoquinone to plastoquinol in Photosystem 1. Michael D. McConnell, John B. Cowgill, Patricia L. Baker, ... Double reduction of plastoquinone to plastoquinol in Photosystem 1. In: Biochemistry. 2011 ; Vol. 50, No. 51. pp. 11034-11046. ... Double reduction of plastoquinone to plastoquinol in Photosystem 1. Biochemistry. 2011 Dec 27;50(51):11034-11046. doi: 10.1021/ ... Double reduction of plastoquinone to plastoquinol in Photosystem 1. / McConnell, Michael D.; Cowgill, John B.; Baker, Patricia ...
So could it be that quinone B turns into plastoquinone on accepting the electrons, and plastoquinone accepts two H+ ions to ... there is no need of conversion of QB to plastoquinone since it is already a plastoquinone. This finding only strengthens the ... But since, in Rhodobacter, QA and QB are UQ10, thus it is not possible to convert QB to plastoquinone by this species. On the ... But I have also read that it is plastoquinone which shuttles the H+ ions in the thylakoid membrane in the form of plastoquinol ...
Nosek, M.; Kornaś, A.; Kuźniak, E.; Miszalski, Z. Plastoquinone redox state modifies plant response to pathogen. Plant Physiol ... showed that plastoquinone regulates plant biotic stress in the redox state, and an accelerated hypersensitive-like response was ... The inner envelope membrane of the chloroplast serves as the site for the synthesis of α-tocopherol and plastoquinone-9 [51], ... observed in the reduced state of plastoquinone [53].. In the molecular function category, O-methyltransferase activity (GO: ...
NADH-plastoquinone oxidoreductase subunit I (chloroplast) [Solanum laciniatum]. 186 aa protein. Accession: YP_010340598.1. GI: ...
... which is activated through the cytochrome b6f complex upon reduction of the plastoquinone pool. Its probable major substrate, ...
15-cis-phytoene + 2 decyl-plastoquinone = 9,15,9-tricis-zeta-carotene + 2 decyl-plastoquinol ...
Plastoquinone is found in the plant cells. It is involved in transport of protons through the inner membrane of chloroplasts in ... Plastoquinone molecules have an antioxidant potential. They can inhibit the oxidation of important molecules by reactive oxygen ... who first proposed to use plastoquinones with lipophilic ions to create the mitochondria targeted antioxidants. Currently the ...
2002) Contributions of the free oxidized and Q(B)-bound plastoquinone molecules to the thermal phase of chlorophyll-a ... Our results suggest that dark reduction of the plastoquinone (PQ) pool, a reserve of central electron carriers of the ... Contribution of plastoquinone quenching to saturation pulse-induced rise of chlorophyll fluorescence in leaves ... A more oxidized plastoquinone pool, that would relieve oxidative stress on Photosystem II. ...
... plastoquinones, chlorophylls and gibberellins. Two GGPP molecules are then condensed into 15-cis-phytoene by PHYTOENE SYNTASE ( ...
Quinones are central to electron transport in photosynthesis (plastoquinone, phylloquinone), and aerobic respiration ( ...
This is a key step in plastoquinone biosynthesis and its inhibition gives rise to bleaching symptoms on new growth. These ... symptoms result from an indirect inhibition of carotenoid synthesis due to the involvement of plastoquinone as a cofactor of ...
Of which oculoglandular improve prenasal somnambulistic deposing barring he jennets Peel? To quizzed several plastoquinone, he ...
... and electron is transferred to plastoquinone. PSII core complex is formed by two reaction center proteins D1 (PsbA) and D2 ( ... cultured cells were maintained in the dark for 5 min to oxidize the plastoquinone pool fully. Initial fluorescence yield of ...
This is a key step in plastoquinone biosynthesis and its inhibition gives rise to bleaching symptoms on new growth. These ... symptoms result from an indirect inhibition of carotenoid synthesis due to the involvement of plastoquinone as a cofactor of ...
... through changes of redox state of plastoquinone pool indicating by differences in 1-qP, Figure 7) or direct effect of diethyl ...
15-cis-phytoene + 2 a plastoquinone <=> 9,9,15-tri-cis-zeta-carotene + 2 a plastoquinol. ...
Photosystem two is a multi subunit protein complex which carries out a photochemical reaction producing reduced plastoquinone ...
Plastoquinone to the rescue!. Plastoquinone is the cargo that gets delivered right to the Mitochondria. It does two very ... Plastoquinone is better than CoQ10. Skulachev initially used CoQ10 but A/B testing it with Plastoquinone in animal experiments ... Plastoquinone to the rescue!. An Anti-Aging Innovation. Vision Biohack. Visomitin. Skin Care. MitoVitan. Exomitin. The Pathway ... Whereas SKQ1 delivers Plastoquinone directly to the interior of the Mitochondria. To quote author and doctor Josh Mitteldorf: ...
Name help_outline a plastoquinone Identifier CHEBI:17757 (CAS: 112055-76-2) help_outline Charge 0 Formula C8H8O2(C5H8)n Search ... a plastoquinone + (n+1) H(+)(in) + NADPH = a plastoquinol + n H(+)(out) + NADP(+). *Reaction information ... Characterization of Nda2, a plastoquinone-reducing type II NAD(P)H dehydrogenase in chlamydomonas chloroplasts.. Desplats C., ... rely on non-photochemical reduction of plastoquinones (PQs). In higher plant chloroplasts, a bacterial-like NDH complex ...
similar to NADH-plastoquinone oxidoreductase subunit K. -. 0. Atcg00480. -. C.G.. S.X.. Please select. ...
We brought to light that single amino acid replacements in the plastoquinone (PQ)-binding niche of the photosystem II D1 ... We brought to light that single amino acid replacements in the plastoquinone (PQ)-binding niche of the photosystem II D1 ...
As a result of MD simulation, the best model obtained in lipid environment had five chlorophylls, two plastoquinones, two ...
Presentation] Plastoquinone-mediated electron transport in a non-photosynthetic plastid of the heterotrophic green alga ...
... prenyl chains of chlorophylls and plastoquinone) [56]. Downstream product of IPP, geranyl pyrophosphate (GPP) is formed under ...
Cationic state of accessory chlorophyll and electron transfer through pheophytin to plastoquinone in photosystem II, Angew. ...
plastoquinone. プラストキノン. Plat. plate. シャーレ. plated. plate tectonics. プレートテクトニクス. platelet. 血小板. Ple. pleiotropy. 多面作用. pleisto- ...

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