Hydrogen: The first chemical element in the periodic table. It has the atomic symbol H, atomic number 1, and atomic weight [1.00784; 1.00811]. It exists, under normal conditions, as a colorless, odorless, tasteless, diatomic gas. Hydrogen ions are PROTONS. Besides the common H1 isotope, hydrogen exists as the stable isotope DEUTERIUM and the unstable, radioactive isotope TRITIUM.Water: A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Hydrogen Bonding: A low-energy attractive force between hydrogen and another element. It plays a major role in determining the properties of water, proteins, and other compounds.Hydrogen Peroxide: A strong oxidizing agent used in aqueous solution as a ripening agent, bleach, and topical anti-infective. It is relatively unstable and solutions deteriorate over time unless stabilized by the addition of acetanilide or similar organic materials.Deuterium: Deuterium. The stable isotope of hydrogen. It has one neutron and one proton in the nucleus.Hydrogen Sulfide: A flammable, poisonous gas with a characteristic odor of rotten eggs. It is used in the manufacture of chemicals, in metallurgy, and as an analytical reagent. (From Merck Index, 11th ed)Water Supply: Means or process of supplying water (as for a community) usually including reservoirs, tunnels, and pipelines and often the watershed from which the water is ultimately drawn. (Webster, 3d ed)Neutrons: Electrically neutral elementary particles found in all atomic nuclei except light hydrogen; the mass is equal to that of the proton and electron combined and they are unstable when isolated from the nucleus, undergoing beta decay. Slow, thermal, epithermal, and fast neutrons refer to the energy levels with which the neutrons are ejected from heavier nuclei during their decay.Neutron Diffraction: The scattering of NEUTRONS by matter, especially crystals, with accompanying variation in intensity due to interference effects. It is useful in CRYSTALLOGRAPHY and POWDER DIFFRACTION.Molecular Structure: The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.Free Radicals: Highly reactive molecules with an unsatisfied electron valence pair. Free radicals are produced in both normal and pathological processes. They are proven or suspected agents of tissue damage in a wide variety of circumstances including radiation, damage from environment chemicals, and aging. Natural and pharmacological prevention of free radical damage is being actively investigated.Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.Molecular Conformation: The characteristic three-dimensional shape of a molecule.Ruthenium Compounds: Inorganic compounds that contain ruthenium as an integral part of the molecule.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).Stereoisomerism: The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Electrons: Stable elementary particles having the smallest known negative charge, present in all elements; also called negatrons. Positively charged electrons are called positrons. The numbers, energies and arrangement of electrons around atomic nuclei determine the chemical identities of elements. Beams of electrons are called CATHODE RAYS.Models, Chemical: Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.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).Fresh Water: Water containing no significant amounts of salts, such as water from RIVERS and LAKES.Body Water: Fluids composed mainly of water found within the body.Quantum Theory: The theory that the radiation and absorption of energy take place in definite quantities called quanta (E) which vary in size and are defined by the equation E=hv in which h is Planck's constant and v is the frequency of the radiation.Protons: Stable elementary particles having the smallest known positive charge, found in the nuclei of all elements. The proton mass is less than that of a neutron. A proton is the nucleus of the light hydrogen atom, i.e., the hydrogen ion.Kinetics: The rate dynamics in chemical or physical systems.Phosphoric Triester Hydrolases: A class of enzymes that catalyze the hydrolysis of one of the three ester bonds in a phosphotriester-containing compound.Solvents: Liquids that dissolve other substances (solutes), generally solids, without any change in chemical composition, as, water containing sugar. (Grant & Hackh's Chemical Dictionary, 5th ed)Deuterium Oxide: The isotopic compound of hydrogen of mass 2 (deuterium) with oxygen. (From Grant & Hackh's Chemical Dictionary, 5th ed) It is used to study mechanisms and rates of chemical or nuclear reactions, as well as biological processes.Zinostatin: An enediyne that alkylates DNA and RNA like MITOMYCIN does, so it is cytotoxic.Gases: The vapor state of matter; nonelastic fluids in which the molecules are in free movement and their mean positions far apart. Gases tend to expand indefinitely, to diffuse and mix readily with other gases, to have definite relations of volume, temperature, and pressure, and to condense or liquefy at low temperatures or under sufficient pressure. (Grant & Hackh's Chemical Dictionary, 5th ed)Thermodynamics: A rigorously mathematical analysis of energy relationships (heat, work, temperature, and equilibrium). It describes systems whose states are determined by thermal parameters, such as temperature, in addition to mechanical and electromagnetic parameters. (From Hawley's Condensed Chemical Dictionary, 12th ed)Crystallography, X-Ray: The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Protein Conformation: The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).Water Purification: Any of several processes in which undesirable impurities in water are removed or neutralized; for example, chlorination, filtration, primary treatment, ion exchange, and distillation. It includes treatment of WASTE WATER to provide potable and hygienic water in a controlled or closed environment as well as provision of public drinking water supplies.Water Pollution: Contamination of bodies of water (such as LAKES; RIVERS; SEAS; and GROUNDWATER.)Androstanes: The family of steroids from which the androgens are derived.Mass Spectrometry: An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.Organic Chemistry Phenomena: The conformation, properties, reaction processes, and the properties of the reactions of carbon compounds.Chemistry: A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.Catalysis: The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.Ruthenium: A hard, brittle, grayish-white rare earth metal with an atomic symbol Ru, atomic number 44, and atomic weight 101.07. It is used as a catalyst and hardener for PLATINUM and PALLADIUM.Hydrogenation: Addition of hydrogen to a compound, especially to an unsaturated fat or fatty acid. (From Stedman, 26th ed)CobamidesCholestanes: Derivatives of the saturated steroid cholestane with methyl groups at C-18 and C-19 and an iso-octyl side chain at C-17.Hydroxyl Radical: The univalent radical OH. Hydroxyl radical is a potent oxidizing agent.Isomerism: The phenomenon whereby certain chemical compounds have structures that are different although the compounds possess the same elemental composition. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Cyclic N-Oxides: Heterocyclic compounds in which an oxygen is attached to a cyclic nitrogen.Chemical Phenomena: The composition, conformation, and properties of atoms and molecules, and their reaction and interaction processes.S-Adenosylmethionine: Physiologic methyl radical donor involved in enzymatic transmethylation reactions and present in all living organisms. It possesses anti-inflammatory activity and has been used in treatment of chronic liver disease. (From Merck, 11th ed)TritiumBinding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Water Pollutants, Chemical: Chemical compounds which pollute the water of rivers, streams, lakes, the sea, reservoirs, or other bodies of water.Alkenes: Unsaturated hydrocarbons of the type Cn-H2n, indicated by the suffix -ene. (Grant & Hackh's Chemical Dictionary, 5th ed, p408)Ethanolamine Ammonia-Lyase: An enzyme that catalyzes the deamination of ethanolamine to acetaldehyde. EC 4.3.1.7.Oxygen: An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.Substrate Specificity: A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.Water Pollutants: Substances or organisms which pollute the water or bodies of water. Use for water pollutants in general or those for which there is no specific heading.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)Mevalonic AcidCyclization: Changing an open-chain hydrocarbon to a closed ring. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)X-Ray Diffraction: The scattering of x-rays by matter, especially crystals, with accompanying variation in intensity due to interference effects. Analysis of the crystal structure of materials is performed by passing x-rays through them and registering the diffraction image of the rays (CRYSTALLOGRAPHY, X-RAY). (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)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.Electron Spin Resonance Spectroscopy: A technique applicable to the wide variety of substances which exhibit paramagnetism because of the magnetic moments of unpaired electrons. The spectra are useful for detection and identification, for determination of electron structure, for study of interactions between molecules, and for measurement of nuclear spins and moments. (From McGraw-Hill Encyclopedia of Science and Technology, 7th edition) Electron nuclear double resonance (ENDOR) spectroscopy is a variant of the technique which can give enhanced resolution. Electron spin resonance analysis can now be used in vivo, including imaging applications such as MAGNETIC RESONANCE IMAGING.Myoglobin: A conjugated protein which is the oxygen-transporting pigment of muscle. It is made up of one globin polypeptide chain and one heme group.Temperature: The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.Spectrometry, Mass, Electrospray Ionization: A mass spectrometry technique used for analysis of nonvolatile compounds such as proteins and macromolecules. The technique involves preparing electrically charged droplets from analyte molecules dissolved in solvent. The electrically charged droplets enter a vacuum chamber where the solvent is evaporated. Evaporation of solvent reduces the droplet size, thereby increasing the coulombic repulsion within the droplet. As the charged droplets get smaller, the excess charge within them causes them to disintegrate and release analyte molecules. The volatilized analyte molecules are then analyzed by mass spectrometry.Isotope Labeling: Techniques for labeling a substance with a stable or radioactive isotope. It is not used for articles involving labeled substances unless the methods of labeling are substantively discussed. Tracers that may be labeled include chemical substances, cells, or microorganisms.Structure-Activity Relationship: The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.Crystallization: The formation of crystalline substances from solutions or melts. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Ions: An atom or group of atoms that have a positive or negative electric charge due to a gain (negative charge) or loss (positive charge) of one or more electrons. Atoms with a positive charge are known as CATIONS; those with a negative charge are ANIONS.Organometallic Compounds: A class of compounds of the type R-M, where a C atom is joined directly to any other element except H, C, N, O, F, Cl, Br, I, or At. (Grant & Hackh's Chemical Dictionary, 5th ed)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.Gas Chromatography-Mass Spectrometry: A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.Hydrogen Cyanide: Hydrogen cyanide (HCN); A toxic liquid or colorless gas. It is found in the smoke of various tobacco products and released by combustion of nitrogen-containing organic materials.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Proteins: Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.Cations: Positively charged atoms, radicals or groups of atoms which travel to the cathode or negative pole during electrolysis.Spectrophotometry: The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.Computer Simulation: Computer-based representation of physical systems and phenomena such as chemical processes.Water Deprivation: The withholding of water in a structured experimental situation.Protein Binding: The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.Chromatography, High Pressure Liquid: Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.Spectrometry, Mass, Fast Atom Bombardment: A mass spectrometric technique that is used for the analysis of a wide range of biomolecules, such as glycoalkaloids, glycoproteins, polysaccharides, and peptides. Positive and negative fast atom bombardment spectra are recorded on a mass spectrometer fitted with an atom gun with xenon as the customary beam. The mass spectra obtained contain molecular weight recognition as well as sequence information.Scattering, Radiation: The diversion of RADIATION (thermal, electromagnetic, or nuclear) from its original path as a result of interactions or collisions with atoms, molecules, or larger particles in the atmosphere or other media. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)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.Chromatography, Thin Layer: Chromatography on thin layers of adsorbents rather than in columns. The adsorbent can be alumina, silica gel, silicates, charcoals, or cellulose. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)NADP: Nicotinamide adenine dinucleotide phosphate. A coenzyme composed of ribosylnicotinamide 5'-phosphate (NMN) coupled by pyrophosphate linkage to the 5'-phosphate adenosine 2',5'-bisphosphate. It serves as an electron carrier in a number of reactions, being alternately oxidized (NADP+) and reduced (NADPH). (Dorland, 27th ed)Ligands: A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)Water Movements: The flow of water in enviromental bodies of water such as rivers, oceans, water supplies, aquariums, etc. It includes currents, tides, and waves.Water SofteningDrinking: The consumption of liquids.Catalase: An oxidoreductase that catalyzes the conversion of HYDROGEN PEROXIDE to water and oxygen. It is present in many animal cells. A deficiency of this enzyme results in ACATALASIA.Oxidants: Electron-accepting molecules in chemical reactions in which electrons are transferred from one molecule to another (OXIDATION-REDUCTION).Deuterium Exchange Measurement: A research technique to measure solvent exposed regions of molecules that is used to provide insight about PROTEIN CONFORMATION.Oxygen Isotopes: Stable oxygen atoms that have the same atomic number as the element oxygen, but differ in atomic weight. O-17 and 18 are stable oxygen isotopes.DNA: A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).Cytochrome P-450 Enzyme System: A superfamily of hundreds of closely related HEMEPROTEINS found throughout the phylogenetic spectrum, from animals, plants, fungi, to bacteria. They include numerous complex monooxygenases (MIXED FUNCTION OXYGENASES). In animals, these P-450 enzymes serve two major functions: (1) biosynthesis of steroids, fatty acids, and bile acids; (2) metabolism of endogenous and a wide variety of exogenous substrates, such as toxins and drugs (BIOTRANSFORMATION). They are classified, according to their sequence similarities rather than functions, into CYP gene families (>40% homology) and subfamilies (>59% homology). For example, enzymes from the CYP1, CYP2, and CYP3 gene families are responsible for most drug metabolism.Sulfides: Chemical groups containing the covalent sulfur bonds -S-. The sulfur atom can be bound to inorganic or organic moieties.Protein Structure, Secondary: The level of protein structure in which regular hydrogen-bond interactions within contiguous stretches of polypeptide chain give rise to alpha helices, beta strands (which align to form beta sheets) or other types of coils. This is the first folding level of protein conformation.Hydrogenase: An enzyme found in bacteria. It catalyzes the reduction of FERREDOXIN and other substances in the presence of molecular hydrogen and is involved in the electron transport of bacterial photosynthesis.Aquaporins: A class of porins that allow the passage of WATER and other small molecules across CELL MEMBRANES.PeroxidasesCystathionine gamma-Lyase: A multifunctional pyridoxal phosphate enzyme. In the final step in the biosynthesis of cysteine it catalyzes the cleavage of cystathionine to yield cysteine, ammonia, and 2-ketobutyrate. EC 4.4.1.1.Sulfur: An element that is a member of the chalcogen family. It has an atomic symbol S, atomic number 16, and atomic weight [32.059; 32.076]. It is found in the amino acids cysteine and methionine.Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.Seawater: The salinated water of OCEANS AND SEAS that provides habitat for marine organisms.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Iron: A metallic element with atomic symbol Fe, atomic number 26, and atomic weight 55.85. It is an essential constituent of HEMOGLOBINS; CYTOCHROMES; and IRON-BINDING PROTEINS. It plays a role in cellular redox reactions and in the transport of OXYGEN.Static Electricity: The accumulation of an electric charge on a objectWater-Electrolyte Balance: The balance of fluid in the BODY FLUID COMPARTMENTS; total BODY WATER; BLOOD VOLUME; EXTRACELLULAR SPACE; INTRACELLULAR SPACE, maintained by processes in the body that regulate the intake and excretion of WATER and ELECTROLYTES, particularly SODIUM and POTASSIUM.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.Rivers: Large natural streams of FRESH WATER formed by converging tributaries and which empty into a body of water (lake or ocean).Water Wells: Constructions built to access underground water.Methane: The simplest saturated hydrocarbon. It is a colorless, flammable gas, slightly soluble in water. It is one of the chief constituents of natural gas and is formed in the decomposition of organic matter. (Grant & Hackh's Chemical Dictionary, 5th ed)Chlorine: A greenish-yellow, diatomic gas that is a member of the halogen family of elements. It has the atomic symbol Cl, atomic number 17, and atomic weight 70.906. It is a powerful irritant that can cause fatal pulmonary edema. Chlorine is used in manufacturing, as a reagent in synthetic chemistry, for water purification, and in the production of chlorinated lime, which is used in fabric bleaching.Nuclear Magnetic Resonance, Biomolecular: NMR spectroscopy on small- to medium-size biological macromolecules. This is often used for structural investigation of proteins and nucleic acids, and often involves more than one isotope.Hydroxides: Inorganic compounds that contain the OH- group.Catalytic Domain: The region of an enzyme that interacts with its substrate to cause the enzymatic reaction.Chemistry, Physical: The study of CHEMICAL PHENOMENA and processes in terms of the underlying PHYSICAL PHENOMENA and processes.Protein Structure, Tertiary: The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.Crystallography: The branch of science that deals with the geometric description of crystals and their internal arrangement. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Electrochemistry: The study of chemical changes resulting from electrical action and electrical activity resulting from chemical changes.Bacterial Proteins: Proteins found in any species of bacterium.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)Aquaporin 1: Aquaporin 1 forms a water-specific channel that is constitutively expressed at the PLASMA MEMBRANE of ERYTHROCYTES and KIDNEY TUBULES, PROXIMAL. It provides these cells with a high permeability to WATER. In humans polymorphisms of this protein result in the Colton blood group antigen.Cattle: Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.Copper: A heavy metal trace element with the atomic symbol Cu, atomic number 29, and atomic weight 63.55.Physicochemical Phenomena: The physical phenomena describing the structure and properties of atoms and molecules, and their reaction and interaction processes.Disinfection: Rendering pathogens harmless through the use of heat, antiseptics, antibacterial agents, etc.Spectrum Analysis, Raman: Analysis of the intensity of Raman scattering of monochromatic light as a function of frequency of the scattered light.Bacteria: One of the three domains of life (the others being Eukarya and ARCHAEA), also called Eubacteria. They are unicellular prokaryotic microorganisms which generally possess rigid cell walls, multiply by cell division, and exhibit three principal forms: round or coccal, rodlike or bacillary, and spiral or spirochetal. Bacteria can be classified by their response to OXYGEN: aerobic, anaerobic, or facultatively anaerobic; by the mode by which they obtain their energy: chemotrophy (via chemical reaction) or PHOTOTROPHY (via light reaction); for chemotrophs by their source of chemical energy: CHEMOLITHOTROPHY (from inorganic compounds) or chemoorganotrophy (from organic compounds); and by their source for CARBON; NITROGEN; etc.; HETEROTROPHY (from organic sources) or AUTOTROPHY (from CARBON DIOXIDE). They can also be classified by whether or not they stain (based on the structure of their CELL WALLS) with CRYSTAL VIOLET dye: gram-negative or gram-positive.Reactive Oxygen Species: Molecules or ions formed by the incomplete one-electron reduction of oxygen. These reactive oxygen intermediates include SINGLET OXYGEN; SUPEROXIDES; PEROXIDES; HYDROXYL RADICAL; and HYPOCHLOROUS ACID. They contribute to the microbicidal activity of PHAGOCYTES, regulation of signal transduction and gene expression, and the oxidative damage to NUCLEIC ACIDS; PROTEINS; and LIPIDS.Dehydration: The condition that results from excessive loss of water from a living organism.Histidine: An essential amino acid that is required for the production of HISTAMINE.Spectrophotometry, Ultraviolet: Determination of the spectra of ultraviolet absorption by specific molecules in gases or liquids, for example Cl2, SO2, NO2, CS2, ozone, mercury vapor, and various unsaturated compounds. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Immersion: The placing of a body or a part thereof into a liquid.Spectroscopy, Fourier Transform Infrared: A spectroscopic technique in which a range of wavelengths is presented simultaneously with an interferometer and the spectrum is mathematically derived from the pattern thus obtained.Sewage: Refuse liquid or waste matter carried off by sewers.Filtration: A process of separating particulate matter from a fluid, such as air or a liquid, by passing the fluid carrier through a medium that will not pass the particulates. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Waste Water: Contaminated water generated as a waste product of human activity.Spectrum Analysis: The measurement of the amplitude of the components of a complex waveform throughout the frequency range of the waveform. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Cysteine: A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.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.Protein Folding: Processes involved in the formation of TERTIARY PROTEIN STRUCTURE.Superoxide Dismutase: An oxidoreductase that catalyzes the reaction between superoxide anions and hydrogen to yield molecular oxygen and hydrogen peroxide. The enzyme protects the cell against dangerous levels of superoxide. EC 1.15.1.1.Zinc: A metallic element of atomic number 30 and atomic weight 65.38. It is a necessary trace element in the diet, forming an essential part of many enzymes, and playing an important role in protein synthesis and in cell division. Zinc deficiency is associated with ANEMIA, short stature, HYPOGONADISM, impaired WOUND HEALING, and geophagia. It is known by the symbol Zn.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.Anaerobiosis: The complete absence, or (loosely) the paucity, of gaseous or dissolved elemental oxygen in a given place or environment. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)Surface Properties: Characteristics or attributes of the outer boundaries of objects, including molecules.Glucose Oxidase: An enzyme of the oxidoreductase class that catalyzes the conversion of beta-D-glucose and oxygen to D-glucono-1,5-lactone and peroxide. It is a flavoprotein, highly specific for beta-D-glucose. The enzyme is produced by Penicillium notatum and other fungi and has antibacterial activity in the presence of glucose and oxygen. It is used to estimate glucose concentration in blood or urine samples through the formation of colored dyes by the hydrogen peroxide produced in the reaction. (From Enzyme Nomenclature, 1992) EC 1.1.3.4.Breath Tests: Any tests done on exhaled air.Water Cycle: Circulation of water among various ecological systems, in various states, on, above, and below the surface of the earth.Nitrogen: An element with the atomic symbol N, atomic number 7, and atomic weight [14.00643; 14.00728]. Nitrogen exists as a diatomic gas and makes up about 78% of the earth's atmosphere by volume. It is a constituent of proteins and nucleic acids and found in all living cells.Solutions: The homogeneous mixtures formed by the mixing of a solid, liquid, or gaseous substance (solute) with a liquid (the solvent), from which the dissolved substances can be recovered by physical processes. (From Grant & Hackh's Chemical Dictionary, 5th ed)Environmental Monitoring: The monitoring of the level of toxins, chemical pollutants, microbial contaminants, or other harmful substances in the environment (soil, air, and water), workplace, or in the bodies of people and animals present in that environment.Plant Transpiration: The loss of water vapor by plants to the atmosphere. It occurs mainly from the leaves through pores (stomata) whose primary function is gas exchange. The water is replaced by a continuous column of water moving upwards from the roots within the xylem vessels. (Concise Dictionary of Biology, 1990)Amides: Organic compounds containing the -CO-NH2 radical. Amides are derived from acids by replacement of -OH by -NH2 or from ammonia by the replacement of H by an acyl group. (From Grant & Hackh's Chemical Dictionary, 5th ed)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.Antioxidants: Naturally occurring or synthetic substances that inhibit or retard the oxidation of a substance to which it is added. They counteract the harmful and damaging effects of oxidation in animal tissues.Mutagenesis, Site-Directed: Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.Heme: The color-furnishing portion of hemoglobin. It is found free in tissues and as the prosthetic group in many hemeproteins.Peptides: Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.Plant Leaves: 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)Carbon Dioxide: A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.Biophysics: The study of PHYSICAL PHENOMENA and PHYSICAL PROCESSES as applied to living things.Biophysical Phenomena: The physical characteristics and processes of biological systems.Hot Temperature: Presence of warmth or heat or a temperature notably higher than an accustomed norm.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Solubility: The ability of a substance to be dissolved, i.e. to form a solution with another substance. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Lactulose: A synthetic disaccharide used in the treatment of constipation and hepatic encephalopathy. It has also been used in the diagnosis of gastrointestinal disorders. (From Martindale, The Extra Pharmacopoeia, 30th ed, p887)Nucleic Acid Conformation: The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.Metals: Electropositive chemical elements characterized by ductility, malleability, luster, and conductance of heat and electricity. They can replace the hydrogen of an acid and form bases with hydroxyl radicals. (Grant & Hackh's Chemical Dictionary, 5th ed)Amitrole: A non-selective post-emergence, translocated herbicide. According to the Seventh Annual Report on Carcinogens (PB95-109781, 1994) this substance may reasonably be anticipated to be a carcinogen. (From Merck Index, 12th ed) It is an irreversible inhibitor of CATALASE, and thus impairs activity of peroxisomes.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Formates: Derivatives of formic acids. Included under this heading are a broad variety of acid forms, salts, esters, and amides that are formed with a single carbon carboxy group.Molecular Dynamics Simulation: A computer simulation developed to study the motion of molecules over a period of time.Water Resources: Environmental reservoirs of water related to natural WATER CYCLE by which water is obtained for various purposes. This includes but is not limited to watersheds, aquifers and springs.Superoxides: Highly reactive compounds produced when oxygen is reduced by a single electron. In biological systems, they may be generated during the normal catalytic function of a number of enzymes and during the oxidation of hemoglobin to METHEMOGLOBIN. In living organisms, SUPEROXIDE DISMUTASE protects the cell from the deleterious effects of superoxides.Permeability: Property of membranes and other structures to permit passage of light, heat, gases, liquids, metabolites, and mineral ions.Peroxides: A group of compounds that contain a bivalent O-O group, i.e., the oxygen atoms are univalent. They can either be inorganic or organic in nature. Such compounds release atomic (nascent) oxygen readily. Thus they are strong oxidizing agents and fire hazards when in contact with combustible materials, especially under high-temperature conditions. The chief industrial uses of peroxides are as oxidizing agents, bleaching agents, and initiators of polymerization. (From Hawley's Condensed Chemical Dictionary, 11th ed)Sodium: A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.Electron Transport: 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)Circular Dichroism: A change from planar to elliptic polarization when an initially plane-polarized light wave traverses an optically active medium. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Recombinant Proteins: Proteins prepared by recombinant DNA technology.Sulfhydryl Compounds: Compounds containing the -SH radical.Horseradish Peroxidase: An enzyme isolated from horseradish which is able to act as an antigen. It is frequently used as a histochemical tracer for light and electron microscopy. Its antigenicity has permitted its use as a combined antigen and marker in experimental immunology.Urea: A compound formed in the liver from ammonia produced by the deamination of amino acids. It is the principal end product of protein catabolism and constitutes about one half of the total urinary solids.Alkynes: Hydrocarbons with at least one triple bond in the linear portion, of the general formula Cn-H2n-2.Whales: Large marine mammals of the order CETACEA. In the past, they were commercially valued for whale oil, for their flesh as human food and in ANIMAL FEED and FERTILIZERS, and for baleen. Today, there is a moratorium on most commercial whaling, as all species are either listed as endangered or threatened.Soil: The unconsolidated mineral or organic matter on the surface of the earth that serves as a natural medium for the growth of land plants.Arsenic: A shiny gray element with atomic symbol As, atomic number 33, and atomic weight 75. It occurs throughout the universe, mostly in the form of metallic arsenides. Most forms are toxic. According to the Fourth Annual Report on Carcinogens (NTP 85-002, 1985), arsenic and certain arsenic compounds have been listed as known carcinogens. (From Merck Index, 11th ed)Nitrogen Isotopes: Stable nitrogen atoms that have the same atomic number as the element nitrogen, but differ in atomic weight. N-15 is a stable nitrogen isotope.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.Manganese: A trace element with atomic symbol Mn, atomic number 25, and atomic weight 54.94. It is concentrated in cell mitochondria, mostly in the pituitary gland, liver, pancreas, kidney, and bone, influences the synthesis of mucopolysaccharides, stimulates hepatic synthesis of cholesterol and fatty acids, and is a cofactor in many enzymes, including arginase and alkaline phosphatase in the liver. (From AMA Drug Evaluations Annual 1992, p2035)Base Pairing: Pairing of purine and pyrimidine bases by HYDROGEN BONDING in double-stranded DNA or RNA.Cystathionine beta-Synthase: A multifunctional pyridoxal phosphate enzyme. In the second stage of cysteine biosynthesis it catalyzes the reaction of homocysteine with serine to form cystathionine with the elimination of water. Deficiency of this enzyme leads to HYPERHOMOCYSTEINEMIA and HOMOCYSTINURIA. EC 4.2.1.22.Desiccation: Removal of moisture from a substance (chemical, food, tissue, etc.).Water Pollutants, Radioactive: Pollutants, present in water or bodies of water, which exhibit radioactivity.Air: The mixture of gases present in the earth's atmosphere consisting of oxygen, nitrogen, carbon dioxide, and small amounts of other gases.Free Radical Scavengers: Substances that influence the course of a chemical reaction by ready combination with free radicals. Among other effects, this combining activity protects pancreatic islets against damage by cytokines and prevents myocardial and pulmonary perfusion injuries.Glutathione: A tripeptide with many roles in cells. It conjugates to drugs to make them more soluble for excretion, is a cofactor for some enzymes, is involved in protein disulfide bond rearrangement and reduces peroxides.Alkanes: The generic name for the group of aliphatic hydrocarbons Cn-H2n+2. They are denoted by the suffix -ane. (Grant & Hackh's Chemical Dictionary, 5th ed)
The hydrogen atoms come mostly from water vapor. In fact, in order to generate aromatic amino acids under primitive earth ... In 1961, Joan Oró found that the nucleotide base adenine could be made from hydrogen cyanide (HCN) and ammonia in a water ... Play media The experiment used water (H2O), methane (CH4), ammonia (NH3), and hydrogen (H2). The chemicals were all sealed ... The liquid water in the smaller flask was heated to induce evaporation, and the water vapour was allowed to enter the larger ...
Like the majority of ice phases (including ice Ih), the hydrogen atom positions are disordered. In addition, the oxygen atoms ... that are largely made of water. S. Klotz, J. M. Besson, G. Hamel, R. J. Nelmes, J. S. Loveday and W. G. Marshall, Metastable ... Hydrogen bonds pass through the center of the water hexamers and thus do not connect the two lattices. Ice VII has a density of ... The structure of water, In Hydrogen bonding, Ed. D. Hadzi and H. W. Thompson (Pergamon Press Ltd, London, 1959) pp 1-6. Note: ...
Saturated fats have all of the carbon atoms! in their fatty acid chains bonded to hydrogen atoms, whereas unsaturated fats have ... About 70% of the non-fat mass of the human body is made of water. Analysis of Adipose Tissue in Relation to Body Weight Loss in ... A molecule of dietary fat typically consists of several fatty acids (containing long chains of carbon and hydrogen atoms), ... Protein molecules contain nitrogen atoms in addition to carbon, oxygen, and hydrogen. The fundamental components of protein are ...
... derived its name from the atoms that make up the water molecule (hydrogen and oxygen). In 1908, the creators of the ... Hydrox is the brand name for a creme-filled chocolate sandwich cookie manufactured by Leaf Brands. It debuted in 1908, and was ... The Carvel ice-cream franchise sold ice-cream goods manufactured with "Hydrox" cookie crumbs until 2012. Carvel used the ... manufactured by Sunshine Biscuits for over ninety years. The similar Oreo cookie, introduced later in 1912, was inspired by the ...
Phthalocyanine green is a phthalocyanine blue pigment where most of the hydrogen atoms are replaced with chlorine. The strongly ... It is made by chlorination of the phthalocyanine blue as a melt of sodium chloride and aluminium chloride, to which chlorine is ... It is a very soft green powder, insoluble in water. Its CAS numbers are 14832-14-5 and 1328-53-6 depending on the extent of ... Copper phthalocyanine green 36 is a variant where some of the chlorine atoms are replaced with bromine. There is evidence that ...
Probe clashes - check for Hydrogen atoms with inappropriate environments (using Molprobity). NCS differences - check for ... Check/Delete waters - check for water molecules which do not fit the density. Check waters by difference map variance Geometry ... Ideal DNA/RNA - build an ideal DNA or RNA fragment. Find ligands - find and fit a model to any small molecule which may be ... Tools for adding atoms to the model: Find waters - add ordered solvent molecules to the model Add terminal residue - extend a ...
Squalene is an oil, made up of carbon and hydrogen atoms, produced by plants and is present in many foods. Squalene is also ... A version without the bacteria, that is only oil in water, is known as Freund's incomplete adjuvant. It helps vaccines release ... making the immune system more robust as it makes use of the additional time by upregulating the production of B and T cells ... The plant extract QS21 is a liposome made up of plant saponins.[13] It is a part of the Shingrix vaccine approved in 2017.[14] ...
... which means the hydrogen atoms can exchange among different oxygen atoms. Semi-heavy water could, in theory, be created via a ... This is because hydrogen atoms (hydrogen-1 and deuterium) are rapidly exchanged between water molecules. Water containing 50% H ... heavy water becomes more prevalent as water molecules trade hydrogen atoms very frequently. Production of pure heavy water by ... Semiheavy water[edit]. Semiheavy water, HDO, exists whenever there is water with light hydrogen (protium, 1. H) and deuterium ( ...
The enol form has C2v symmetry, meaning the hydrogen atom is shared equally between the two oxygen atoms. In the gas phase, the ... It is also a building block for the synthesis of heterocyclic compounds. The keto and enol forms of acetylacetone coexist in ... Since the metal complex carries no electrical charge, it is often insoluble in water but soluble in nonpolar organic solvents. ... Both oxygen atoms bind to the metal to form a six-membered chelate ring. In some cases the chelate effect is so strong that no ...
This law acknowledged that any hydrogen atom even as part of a radical could be substituted by a halogen. Eventually Frankland ... Another was water type as promoted by Alexander William Williamson. Jean-Baptiste Dumas and Auguste Laurent (an early supporter ... making trivalent carbon obsolete for the time being. In 1900 Moses Gomberg unexpectedly discovered true trivalent carbon and ... In his Etherin theory he observed that ether consisted of two equivalents of ethylene and one equivalent of water and that ...
This made it possible to experimentally determine the internuclear distance between the hydrogen atoms in water. In solids with ... 16, 327 (1948); doi:10.1063/1.1746878; http://link.aip.org/link/JCPSA6/v16/i4/p327/s1 Diffusion of Water Molecules in Hydrates ... vacant positions, dipole coupling is averaged partially due to water diffusion which proceeds according to the symmetry of the ...
In most medical applications, protons (hydrogen atoms) in tissues containing water molecules create a signal that is processed ... The excited hydrogen atoms emit a radio frequency signal, which is measured by a receiving coil. The radio signal may be made ... Hydrogen atoms exist naturally in people and other biological organisms in abundance, particularly in water and fat. For this ... Moreover, the nucleus of any atom that has a net nuclear spin and that is bonded to a hydrogen atom could potentially be imaged ...
Different experiments have suggested that water is created anywhere from 5-33% of the time. Water formation on grains is still ... The major product is dissociation into three hydrogen atoms, which occurs roughly 75% of the time. The minor product is H2 and ... The arrangement of the hydrogen atoms in the molecule is an equilateral triangle. The molecule has a resonance structure which ... They also used an early form of mass spectrometry to study hydrogen discharges. They found that as the pressure of hydrogen ...
The presence of two lone pairs of electrons on the oxygen atoms makes hydrogen bonding with water molecules possible. ... 4-dioxane are miscible in water because of the more exposed oxygen atom for hydrogen bonding as compared to linear aliphatic ... This reactivity is similar to the tendency of ethers with alpha hydrogen atoms to form peroxides. Reaction with chlorine ... Ethers are a class of organic compounds that contain an ether group-an oxygen atom connected to two alkyl or aryl groups. They ...
... fraction of the hydrogen atoms in the hydrocarbons with fluorine atoms to achieve lower coefficients of friction and high water ... Moisture content: The percentage of mass that is liquid water and may create suction friction with the base of the ski as it ... With these waxes, some, most, or all the hydrogen atoms in the hydrocarbons have been replaced with fluorine atoms. This new ... Conceptual representation of sliding friction over snow, as a function of water film thickness, created by passage of a ski or ...
Saturated fats have all of the carbon atoms in their fatty acid chains bonded to hydrogen atoms, whereas unsaturated fats have ... The macronutrients (excluding fiber and water) provide structural material (amino acids from which proteins are built, and ... Protein molecules contain nitrogen atoms in addition to carbon, oxygen, and hydrogen. The fundamental components of protein are ... Molecules of carbohydrates and fats consist of carbon, hydrogen, and oxygen atoms. Carbohydrates range from simple ...
Saturated fats have all of the carbon atoms in their fatty acid chains bonded to hydrogen atoms, whereas unsaturated fats have ... The macronutrients (excluding fiber and water) provide structural material (amino acids from which proteins are built, and ... These reference values include water from drinking water, other beverages, and from food. About 80% of our daily water ... A molecule of dietary fat typically consists of several fatty acids (containing long chains of carbon and hydrogen atoms), ...
... and nitrogen atoms (in amine functional groups) in the guest molecules lead to transient hydrogen bonds and misoriented water ... Dislocations of ice Ih along a slip plane create pairs of Bjerrum defects, one D defect and one L defect. Nonpolar molecules ... The unfavorable defect strain is resolved when a water molecule pivots about an oxygen atom to produce hydrogen bonds with ... Although there is no hydrogen bonding of water molecules when methane is the guest molecule of the clathrate, guest-host ...
The presence of two lone pairs of electrons on the oxygen atoms makes hydrogen bonding with water molecules possible. Cyclic ... 4-dioxane are miscible in water because of the more exposed oxygen atom for hydrogen bonding as compared to linear aliphatic ... This reactivity is similar to the tendency of ethers with alpha hydrogen atoms to form peroxides. Reaction with chlorine ... Ethers can again be classified into two varieties: if the alkyl groups are the same on both sides of the oxygen atom, then it ...
This is because hydrogen atoms (hydrogen-1 and deuterium) are rapidly exchanged between water molecules. Water containing 50% H ... This makes semiheavy water far more common than "normal" heavy water. The freezing point of semiheavy water is close to the ... In regular water, about 1 molecule in 3,200 is HDO (one hydrogen in 6,400 is D). By comparison, heavy water D2O occurs at a ... Semiheavy water is the result of replacing one of the protium in light water to deuterium. It exists whenever there is water ...
First two hydrogen-atoms are added to the azoxybenzene (1). The first one goes to the negative charged oxygen-atom. The second ... In the next step water is added and an oxonium ion (3) is built. After proton donation, the compound is aromatic again and the ... The phenolic oxygen atom in the product is not the oxygen atom in the reactant but provided by solvent, based on isotopic ... In the first part of the reaction, two equivalents of acid tease the oxygen atom away from the azoxy group. The resulting ...
Under certain conditions a hydrogen atom in a molecule can form a second, weaker, bond with an atom or group of atoms in ... and even raises water's boiling point high enough to make a decent cup of tea."[15] ... two of the nonmetals-hydrogen and helium-make up over 99 percent of the observable universe.[1] Another nonmetal, oxygen, makes ... Hydrogen and helium are estimated to make up approximately 99 per cent of all ordinary matter in the universe. Less than five ...
They are also made up of carbon, oxygen and hydrogen atoms. Lignins are complex compounds that form the older parts of wood, ... The water content of most plant residues is in the range of 60% to 90%. The dry matter consists of complex organic material ... Organic compounds found in plant residues include: Carbohydrates are made up of carbon, hydrogen and oxygen, and range in ... composed mainly of carbon, oxygen and hydrogen. Although these three elements make up about 92% of the dry weight of the ...
As the hydrogen atoms in water coolants are bombarded with neutrons, some absorb a neutron to become deuterium, and then some ... Water contaminated with tritium sometimes leaks to groundwater by accident or by official approval The fuel rods create high ... If that hydrogen accumulates in sufficient quantities-concentrations of 4 percent or more in the air, then that hydrogen can ... Heavy water reactors (CANDU) use deuterium oxide which has identical properties to ordinary water but much lower neutron ...
The glass of water one last drank has many hydrogen atoms, each of which is an instance of hydrogen. Hydrogen itself, a class ... RDF also provides rdf:Property as a way to create properties beyond those defined in the built-in vocabulary. Properties can be ... RDFS thus makes it possible for vocabularies to represent taxonomies, also known as subsumption hierarchies or concept ... Metaclasses are often modeled by setting them as the object of claims involving rdf:type and rdfs:subClassOf-built-in ...
An aldehyde differs from a ketone because of its hydrogen atom attached to its carbonyl group, making aldehydes easier to ... Because the carbonyl group interacts with water by hydrogen bonding, ketones are typically more soluble in water than the ... Ketones are hydrogen-bond acceptors. Ketones are not usually hydrogen-bond donors and cannot hydrogen-bond to themselves. ... Ketones don't have a hydrogen atom bonded to the carbonyl group, and are more resistant to oxidation. They are only oxidized by ...
Iron is used to make a number of residential and industrial products, including bicycles, buildings, skyscrapers, bridges, ... Where can I find a picture of the Bohr-Rutherford diagram of the hydrogen atom?. ... What are some of the chemical properties of water?. * Q: ... A: Metals are used to build bridges, plumb homes and make ... Gates, railings and fences are also made o... Full Answer , Filed Under: * Atoms & Molecules ...
Creating STEM Knowledge and Innovations to Solve Global Issues Like Water, Food, and Energy. Illinois Mathematics and Science ... enclosing hydrogen atoms (in red). Three hydrogen atoms are shown interacting at surprisingly small hydrogen-hydrogen atomic ... Superconducting, high temperature superconductor, low pressure superconductor, metal hydride, Hydrogen atoms, hydrogen storage ... Atom or noise? New method helps cryo-EM researchers tell the difference. Cryogenic electron microscopy can in principle make ...
Creating STEM Knowledge and Innovations to Solve Global Issues Like Water, Food, and Energy. Illinois Mathematics and Science ... enclosing hydrogen atoms (in red). Three hydrogen atoms are shown interacting at surprisingly small hydrogen-hydrogen atomic ... Superconducting, high temperature superconductor, low pressure superconductor, metal hydride, Hydrogen atoms, hydrogen storage ... These smaller spacings between the atoms might allow packing significantly more hydrogen into the material to a point where it ...
... the solvent is the water. A solvent is a substance that completely dissolves another substance in it. A solute is the substance ... In this equation, two hydrogen atoms react with ... Full Answer , Filed Under: * Chemical Equations ... What Is the Chemical Equation for Water?. A: The chemical equation formula for water is expressed as H2O, but also is ... The charges help to attract other atoms. The covalent bonds hold the water together while separating the molecules of ...
What makes up a molecule of water? 1 oxygen atom. 2 hydrogen atoms ... Because hydrogen atoms in ice are more "ordered" making ice less dense ... What makes water molecules polar? (What end is positive? What end is negative?) ... Our mission is to create a smarter world by simplifying and accelerating the learning process. © 2018 Bold Learning Solutions. ...
Hydrogen atoms, excluding those of water, are omitted for clarity. Figure 3. Structure of (R)-MOF-2 in an asymmetric unit and ... The guest molecules are bound to the water molecules by the hydrogen bonds of O21-H…O18 and O22-H…O19. ... An asymmetric unit of (R)-MOF-2 contains two Mn2+ ions, two (R)-22−groups, four DMF molecules, four water molecules, and two ... Create a SciFeed alert for new publications. With following keywords. homochiral metal-organic framework. ...
The manufacturing of water is a concept that will help the development of places with water shortages. Learn about the concept ... Water is made of two hydrogen atoms attached to an oxygen atom. This seems like pretty basic chemistry, so why dont we just ... To create water, oxygen and hydrogen atoms must be present. Mixing them together doesnt help; youre still left with just ... And as water becomes scarcer, the process of joining hydrogen atoms to oxygen atoms may become more attractive than it is ...
Scientists create a new form of matter-superionic water ice Dinosaur, mammal tracks discovered in NASAs backyard ... Galactic map shows hydrogen atoms in Milky Way in breathtaking photo. By Rachael Lallensack. Oct. 21, 2016 , 4:45 PM. ... An international team of astronomers joined forces to create the most detailed map of neutral hydrogen, the universes most ... The clarity of the image could help researchers find out how our galaxy gets the gas necessary to build new stars, and where ...
A molecule of water has two hydrogen atoms and one oxygen atom. Imagine you have, say, ten atoms of hydrogen and five of oxygen ... He was studying chemistry back in the 1800s and saw (for example) that if you want to make water with hydrogen and oxygen and ... an atom of hydrogen has a different mass than an atom of oxygen-hydrogen is way lighter than oxygen, so a gram of hydrogen has ... A water molecule has two atoms of hydrogen and one of oxygen.. Photo by Shutterstock/Lightspring. ...
Proteins are food and body components made of amino acids. Proteins contain carbon, hydrogen, oxygen, nitrogen, and other atoms ... Water is the universal solvent, and chemically known as H2O. The body is composed of about 60% water. Water needs are about 9 ... Lipids are compounds containing carbon and hydrogen, a little oxygen, and sometimes other atoms. Lipids dissolve in benzene, ... Carbohydrates are a compound containing carbon, hydrogen, and oxygen atoms. Most carbohydrates are known as sugars, starches, ...
A water molecule is made of two hydrogen atoms and one oxygen atom. In this activity, you and your family members will make ... To make a water molecule, ask an adult to help you use two small, colored marshmallows for the hydrogen atoms and one large, ... you have been learning how atoms join with other atoms to form molecules. You cant see molecules, but you can make models of ... How is your model like a real water molecule? Why do you think a large marshmallow was chosen to represent an oxygen atom, ...
Dive in and test your knowledge of water...and see whether you sink or swim. ... Even though water exists in three states, there is only one correct answer to the questions in this quiz. ... is water made?. Answer: A molecule of water, also known as H. 2O, is made up of two hydrogen atoms and one oxygen atom.. ... Answer: Each molecule of water is made up of two hydrogen atoms and one oxygen atom.. Question: Which of these forms does water ...
If you wanted to make an accurate scale model of the hydrogen atom and decided that the nucleus would have a di.... Chemistry ... With how many water molecules can a given alcohol molecule hydrogen-bond? a. 2 b. 3 c. 4 d. no correct response. General, ... If a molecule donate only one hydrogen atom then the acid is called a monoprotic acid. ... Assign oxidation states for all atoms in each of the following compounds. a. KMnO4 b. NiO2 c. Na4Fe(OH)6 d. (NH.... Chemistry ...
... which means the hydrogen atoms can exchange among different oxygen atoms. Semi-heavy water could, in theory, be created via a ... This is because hydrogen atoms (hydrogen-1 and deuterium) are rapidly exchanged between water molecules. Water containing 50% H ... heavy water becomes more prevalent as water molecules trade hydrogen atoms very frequently. Production of pure heavy water by ... Semiheavy water[edit]. Semiheavy water, HDO, exists whenever there is water with light hydrogen (protium, 1. H) and deuterium ( ...
Learn about the property of water known as surface tension that allows insects to walk on water. Core concepts involve ... A water molecule is made up of one oxygen atom and two hydrogen atoms. These atoms connect by sharing electrons. Due to the ... This pulling creates a thin layer of water molecules that link together creating the surface tension we will see in this ... forces that connect the hydrogen atoms to the oxygen atoms, a water molecule tends to have one side that is little more ...
What is Water? Molecule made up of two hydrogen atoms and one oxygen atom (H2O). Forms a bent-shaped triangular molecule. ... States of Water Water.... About 70% of our total body weight is water. The physical and chemical properties of water have ... and two hydrogen atoms hold small positive charge (dipole-dipole force). Attracted to each other creating hydrogen bonds. ... spilled water, this is how water makes things wet. Water clings to living things. Most plants have adapted to take advantage of ...
... two hydrogen atoms bond to an oxygen and create H20. However in deuterated water, deuterium atoms replace the hydrogen atoms. ... Deuterium labeled water (D2O), also known as heavy water is physically and chemically very similar to ordinary drinking water. ... This neutron gives the atom extra weight, hence the name heavy water. This extra weight can be detected in the lab with very ... Deuterium is in fact already in the water we drink daily. It is not radioactive, and it occurs naturally at a concentration of ...
... hydrogen is truly in a class by itself. It does not belong to any family of elements, and though it is a nonmetal, it appears ... HYDROGEN CONCEPT First element on the periodic table [1], ... s about one out of every 6,700 atoms. Water made out of ... there are twice as many hydrogen atoms in water as there are oxygen atoms.) Because the stars are mostly made of hydrogen, it ... Hydrogen occurs on the Earth primarily in the form of water. Every molecule of water (H2O) contains two hydrogen atoms and one ...
It is polar because it has twohydrogen atoms bonded uniquely to one atom of oxygen causingdifferent charges in different areas. ... What type of molecule is a water molecule? A water molecule is made up of two hydrogen atoms attached to one oxygen atom. The ... Is a water molecule? If you meant is water a molecule then - yes. It consists of 2 atoms of hydrogen and 1 atom of oxygen. ... There is 1 molecule of water in a molecule of water. That 1 molecule is comprised of 1 Oxygen atom and 2 Hydrogen atoms. ...
Properties of Water. There are 2 hydrogen atoms joined to 1 oxygen atom. The polarity of water results in weak electrical ... Water is slightly positive on one side and negative on the other... this makes water a polar molecule Surface Tension: How ... Hydrogen bonds: the attraction of hydrogen (+ charge) with a negative (-) atom or molecule.. ,, water molecules Water is a ... Water has high surface tension because of the hydrogen bonds. Ex: water travels AGAINST gravity to get water to the leaves on a ...
... streams even underground water while pure water can rarely be found..if the water is pure it can dissolve lots of things. ... natural water can be found around you..in rivers, ... Pure water is? H2O, 2 hydrogen atoms and 1 oxygen atom. Water ... an element is made out of only one type if atom. ... What is pure water? Pure water is H20, Two Hydrogen Atoms With ... Differentiate natural water from pure water? Differentiate natural water from pure water?. ...
When one of these oxygen atoms combined with two hydrogen atoms, they made molecules of water. These microscopic boomerang ... They burn hydrogen with oxygen to make energy and water. Another way to make water is as a byproduct of some chemical reactions ... If you are really keen, you can make your own water. Just get hydrogen and oxygen, and set them alight with a match. You get a ... But these are really uncommon ways to get your water.. Instead, 99.99999+% of the water we drink today was made a long long ...
Water is a compound made up of two hydrogen atoms and one oxygen atom. When the universe was young there were only hydrogen ... The comet water contained proportionally more deuterium - an isotope of hydrogen - than Earthly water does, although of course ... And of course we would like to know what sort of water comets carry. There are different forms of oxygen and hydrogen, called ... Then stars formed from that hydrogen, and started getting the energy needed to shine from nuclear fusion. Hydrogen was ...
the water molecule is made up of two hydrogen atoms and one oxygen atom. As oxygen ... INTRODUCTION INTRODUCTION WATER- THE NEED OF LIFE Life as we know it cannot exist without water. 71 % of the Earth is covered ... modern processed foods and traditional foods, but their manufacturing technology, process control and manufacturing and ... The main focus of your strategy must make sure that your product should fulfill the demands of the consumers and as well as it ...
  • Nevertheless, the various differences in deuterium-containing water (especially affecting the biological properties) are larger than in any other commonly occurring isotope-substituted compound because deuterium is unique among heavy stable isotopes in being twice as heavy as the lightest isotope. (wikipedia.org)
  • Since then, heavy water has been an essential component in some types of reactors, both those that generate power and those designed to produce isotopes for nuclear weapons. (wikipedia.org)
  • The only element whose isotopes have names, hydrogen has long been considered as a potential source of power and transportation: once upon a time for airships, later as a component in nuclear reactions - and, perhaps in the future, as a source of abundant clean energy. (encyclopedia.com)
  • Hydrogen has two stable isotopes - forms of the element that differ in mass. (encyclopedia.com)
  • Protium (the name is only used to distinguish it from the other isotopes) accounts for 99.985% of all the hydrogen that appears in nature. (encyclopedia.com)
  • The fact that hydrogen's isotopes have separate names, whereas all other isotopes are designated merely by element name and mass number (for example, "carbon-12") says something about the prominence of hydrogen as an element. (encyclopedia.com)
  • Higher isotopes of hydrogen are only created in artificial accelerators and reactors and have half lives around the order of 10−22 seconds. (wikipedia.org)
  • The formulas below are valid for all three isotopes of hydrogen, but slightly different values of the Rydberg constant (correction formula given below) must be used for each hydrogen isotope. (wikipedia.org)
  • All elements have isotopes and the number ranges from three for hydrogen to over 30 for elements such as caesium and barium. (wikibooks.org)
  • An international team of astronomers joined forces to create the most detailed map of neutral hydrogen , the universe's most abundant element, released late last month in Astronomy and Astrophysics . (sciencemag.org)
  • In a new study from the U.S. Department of Energy's ( DOE ) Argonne National Laboratory and Harvard University, scientists have for the first time been able to see an especially important step in the water-splitting process, which may bring us closer to abundant solar energy for all. (anl.gov)
  • Recently, much scientific attention has focused on cobalt, a relatively abundant and inexpensive catalyst that - in the right circumstances - can serve as an escort to an electronic dance between hydrogens and oxygens. (anl.gov)
  • It was first theoretically predicted more than 30 years ago, and although it has never been seen until now, scientists think it might be among the most abundant forms of water in the universe. (wired.com)
  • One of the largest obstacles to producing fuel cells made for hydrogen, the Universe's most abundant element, is the energy-intensive process it currently requires, negating hydrogen's clean energy qualities. (bigthink.com)
  • It describes a novel hydrogen-related energy that's cheap, abundant, and generates no pollution or greenhouse gases. (innerself.com)
  • ON Nov. 1, 1952, when a thermonuclear bomb equivalent to 10 million tons of TNT was detonated at Eniwetok atoll in the Pacific, an apocalyptic nightmare was born, but also a great dream: the possibility of generating cheap and abundant electricity by fusing together hydrogen nuclei. (nytimes.com)
  • Now cheese is not a fundamental particle, but you can explain that atoms combine in various arrangements to form different materials. (nps.gov)
  • Soil bacteria convert the ammonium into ammonium nitrate, a form plants can use to make nutrient sugars. (gardenguides.com)
  • You could potentially use this to clean water from a pond or river that has bacteria and dirt particles," said Sangwoo Shin, an assistant professor of mechanical engineering at the University of Hawaii at Manoa. (nanowerk.com)
  • Popular belief is that Hydrogen peroxide kills bacteria in cuts, and scrapes, because it bubbles when it is poured into the wounds. (hubpages.com)
  • Some researchers do not believe that hydrogen peroxide kills bacteria. (hubpages.com)
  • Another article I read says that hydrogen peroxide does kill bacteria, because its an oxidizer. (hubpages.com)
  • The article does say that, yes, hydrogen peroxide does kill bacteria. (hubpages.com)
  • The goal of Wastewater Bacteria is to enable plant operators to achieve the twofold basic objectives of wastewater treatment-to degrade organic wastes to a level where a significant, dissolved oxygen demand is not exerted upon receiving waters and to remove nutrients to levels where photosynthetic organisms in receiving waters are limited in their growth. (google.it)
  • Toxins are poisons produced by plants, animals and bacteria or found naturally in the air, water and soil. (answersingenesis.org)
  • Recently at the Laboratory for Laser Energetics in Brighton, New York, one of the world's most powerful lasers blasted a droplet of water, creating a shock wave that raised the water's pressure to millions of atmospheres and its temperature to thousands of degrees. (wired.com)
  • Since water's greatest density occurs at 4°C and as water cools and freezes into ice it becomes less dense. (flashcardmachine.com)
  • The gas, which mixes with the water in a system of channels, temporarily changes the water's chemistry. (nanowerk.com)
  • This 'stickiness'-which comes from a force called hydrogen bonding-accounts for many of water's most amazing traits. (amnh.org)
  • Seemingly simple ideas such as how water freezes are not understood because of water's unique properties. (maths.org)
  • Indeed, nuclear fusion of hydrogen in the stars is the ultimate source for the 90-odd elements that occur in nature. (encyclopedia.com)
  • After a few hundred million years, the first generation of stars sparked into existence, and as part of their nuclear burning, made oxygen. (abc.net.au)
  • Then stars formed from that hydrogen, and started getting the energy needed to shine from nuclear fusion. (gc.ca)
  • Deuterium is stable and makes up 0.0115% of naturally occurring hydrogen and is used in industrial processes like nuclear reactors and Nuclear Magnetic Resonance. (wikipedia.org)
  • In order to scan nuclear reactors for forbidden uses such as weapon-making, researchers are now working on remotely monitoring nuclear activity by focusing on ethereal particles known as antineutrinos. (livescience.com)
  • Nuclear fission reactors are the most intense man-made source of antineutrinos,' said physicist Nathaniel Bowden at Lawrence Livermore National Laboratory. (livescience.com)
  • Now researchers are testing two prototype above-ground antineutrino detectors at the San Onofre Nuclear Generating Station in California, one using a solid plastic scintillator, the other using water. (livescience.com)
  • All of these terms are related by the fact that they all have something to do with nuclear elements, either natural or man-made. (howstuffworks.com)
  • Hydrogen can be produced economically from excess wind/solar power, nuclear heat or fossil fuels with CCS. (theenergycollective.com)
  • MegaHydrate™ is the ultimate hydrogen product (even better than molecular hydrogen), greatly enhances the production of ATP (cellular energy) in the body, is the most powerful antioxidant available, and is the key that unlocks the potential of water as the medium for nutrient replenishment and waste removal at the cellular level. (integratedhealth.com)
  • An international team of researchers has discovered the hydrogen atoms in a metal hydride material are much more tightly spaced than had been predicted for decades-a feature that could possibly facilitate superconductivity at or near room temperature and pressure. (newswise.com)
  • The clarity of the image could help researchers find out how our galaxy gets the gas necessary to build new stars, and where neighboring dwarf galaxies may be located. (sciencemag.org)
  • Researchers have used heavy water since 1934 as a safe and effective tool in clinical trials. (clinicaltrials.gov)
  • The researchers found evidence of water in nearly all of the large pyroclastic deposits that had been previously mapped across the Moon's surface, including deposits near the Apollo 15 and 17 landing sites where the water-bearing glass bead samples were collected. (abovetopsecret.com)
  • Additional laser beams generate an x-ray flash off an iron foil, allowing the researchers to take a snapshot of the compressed water layer. (wired.com)
  • The researchers saw claims that cold brew has decreased acidity, making it easier on the stomach. (northwestern.edu)
  • The researchers believe that when hot water comes in contact with the coffee grind, it extracts more acids than cold water does, thus giving hot coffee more acids than cold brew, even though they have similar acidity concentrations overall. (northwestern.edu)
  • Researchers at Princeton University have found a technique for using carbon dioxide in a low-cost water treatment system that eliminates the need for costly and complex filters. (nanowerk.com)
  • By taking advantage of this migration, the researchers are able to split the water stream and filter out suspended particles. (nanowerk.com)
  • In a paper published May 2 in the journal Nature Communications ( 'Membraneless water filtration using CO 2 ' ), the researchers describe how they built a laboratory-scale filter that removed particles three orders of magnitude (1,000-fold) more efficiently than conventional microfiltration systems. (nanowerk.com)
  • The researchers' device takes advantage of this electric sorting by drawing the contaminants to one side of the flow and then splitting the water into two channels. (nanowerk.com)
  • The researchers thought of the technique while examining the motion of colloidal particles in a salt gradient -- a term for the interface between bodies of salt and fresh water. (nanowerk.com)
  • Shin said the researchers were observing the motion of charged particles in the salt water when they realized the phenomenon could be useful as a filter. (nanowerk.com)
  • So the researchers thought to substitute carbon dioxide because it is cheap, not harmful for humans to ingest and as easy to remove from water as opening a can of soda. (nanowerk.com)
  • The researchers said using a soluble gas as a method of controlling particles in a solution could lead to other industrial or scientific applications beyond water filtration. (nanowerk.com)
  • These researchers are the ones, who have studied and still are studying the effects of hydrogen peroxide. (hubpages.com)
  • Researchers have advised against using hydrogen peroxide for cuts and scrapes, because hydrogen peroxide damages healthy cells that are needed for the healing of the wound. (hubpages.com)
  • The finding of water in these ancient deposits, which are believed to consist of glass beads formed by the explosive eruption of magma coming from the deep lunar interior, bolsters the idea that the lunar mantle is surprisingly water-rich. (abovetopsecret.com)
  • For example, one-dimensional helical metal-organic framework built from a chiral octahydrobinaphthalene-derived dicarboxylic acid showed the intense broad photoluminescence emission in the solid state [ 46 ]. (mdpi.com)
  • Herein, we report the synthesis and X-ray crystal structure of the one-dimensional helical homochiral MOF, ( R )-MOF -2 , constructed from ( R )-2,2′-dihydroxy-1,1′-binaphthyl-3,3′-dicarboxylic acid ( 2 ) ( Scheme 2 ). (mdpi.com)
  • If a molecule donate only one hydrogen atom then the acid is called a monoprotic acid. (bartleby.com)
  • When ionized hydrogen is written as "H+" as in the solvation of classical acids such as hydrochloric acid, the hydronium ion, H3O+, is meant, not a literal ionized single hydrogen atom. (wikipedia.org)
  • If the soil water tested has more hydrogen particles than oxygen combined with hydrogen, then the soil is acid. (gardenguides.com)
  • It begins with the Swiss-German physician Paracelsus about five hundred years ago noticing that a flammable gas formed when iron reacted with a certain acid added to water. (innerself.com)
  • This seems like pretty basic chemistry, so why don't we just smash them together and solve the world-'s water ills? (howstuffworks.com)
  • He was studying chemistry back in the 1800s and saw (for example) that if you want to make water with hydrogen and oxygen and wanted no gas left over when you're done, you need exactly twice the volume of hydrogen gas as you did oxygen. (slate.com)
  • However, this was a largely philosophical notion, and it was not until the emergence of atomic theory and modern chemistry that scientists began to postulate that particles, when taken in combination, produced the basic building blocks of all things. (universetoday.com)
  • Then in 1661, naturalist Robert Boyle argued in a treatise on chemistry - titled " The Sceptical Chymist "- that matter was composed of various combinations of "corpuscules", rather than earth, air, wind, water and fire. (universetoday.com)
  • The Periodic Table of Elements you see in chemistry class is a list of the elements found in nature plus a number of man-made elements. (howstuffworks.com)
  • Carbon dioxide changes the chemistry of contaminated water, which causes particles to move to one side of a channel and splitting the flow into clean and dirty streams. (nanowerk.com)
  • After having taken Organic Chemistry 1 and 2 at the University, I found that Organic Chemistry really is the knowledge of what atoms or atomic structures will do when encountering another set of atoms or atomic structures. (umich.edu)
  • The first thing needed as a foundation for the study of Organic Chemistry, is the knowledge of the structure of the atom. (umich.edu)
  • What is the nucleus made of? (brainscape.com)
  • Experiments by Ernest Rutherford in 1909 showed the structure of the atom to be a dense, positive nucleus with a light, negative charge orbiting around it. (wikipedia.org)
  • From a size point of view, the radius of an atom is about 10 -10 m while the radius of a nucleus is about 10 -14 m, i.e. about ten thousand times smaller. (wikibooks.org)
  • Remember though that this is a simplified illustration given what we noted earlier about the size of a nucleus compared with that of an atom. (wikibooks.org)
  • Sometimes the center of an atom (its nucleus) has too much energy in it. (iem-inc.com)
  • The problem of uniformly squeezing hydrogen plasma fuel -- a hot, electrically charged gas -- to the needed density has proved to be comparable but far trickier than squeezing a large balloon to the size of a pea, using fingers alone. (nytimes.com)
  • Answer: The Atlantic Ocean receives the waters of several of the world's largest rivers: the Nile, Amazon, Congo, Mississippi, Niger, Danube, and Orinoco, plus much of the flow from Arctic glaciers. (britannica.com)
  • A California company has announced its plan to build the world's first prototype for a ' nanotechnology-based, zero-carbon' process for producing renewable hydrogen and natural gas. (bigthink.com)
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