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Homoisocitric Acid
Homoisocitric acid is an isomer of homocitric acid in which the hydroxyl is on the 2 position. It is an intermediate in the α-aminoadipate pathway of lysine biosynthesis where it is produced by homocitrate synthase and is a substrate for homoaconitase. Homoisocitrate is an anion, salt, or ester of homoisocitric acid. See also * Homoaconitic acid * Adipic acid Adipic acid or hexanedioic acid is the organic compound with the formula (CH2)4(COOH)2. From an industrial perspective, it is the most important dicarboxylic acid: about 2.5 billion kilograms of this white crystalline powder are produced annually, ... References {{Reflist Tricarboxylic acids Alpha hydroxy acids ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homocitric Acid
Homocitric acid is an organic compound with the formula HOC(CO2H)(CH2CO2H)(C2H4CO2H). This tricarboxylic acid occurs naturally as a component of the iron-molybdenum cofactor of certain nitrogenase proteins. Biochemists often refer to this cofactor as homocitrate, which is the conjugate bases that predominate in neutral aqueous solutions of this species. The molecule is related to citric acid by the addition of one methylene unit, hence the prefix "homo." Unlike citric acid, homocitric acid is chiral. The acid exists in equilibrium with the lactone Lactones are cyclic carboxylic esters, containing a 1-oxacycloalkan-2-one structure (), or analogues having unsaturation or heteroatoms replacing one or more carbon atoms of the ring. Lactones are formed by intramolecular esterification of the co .... : See also * Homoisocitric acid References Alpha hydroxy acids Chelating agents Tricarboxylic acids {{biochem-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lysine
Lysine (symbol Lys or K) is an α-amino acid that is a precursor to many proteins. It contains an α-amino group (which is in the protonated form under biological conditions), an α-carboxylic acid group (which is in the deprotonated −COO− form under biological conditions), and a side chain lysyl ((CH2)4NH2), classifying it as a basic, charged (at physiological pH), aliphatic amino acid. It is encoded by the codons AAA and AAG. Like almost all other amino acids, the α-carbon is chiral and lysine may refer to either enantiomer or a racemic mixture of both. For the purpose of this article, lysine will refer to the biologically active enantiomer L-lysine, where the α-carbon is in the ''S'' configuration. The human body cannot synthesize lysine. It is essential in humans and must therefore be obtained from the diet. In organisms that synthesise lysine, two main biosynthetic pathways exist, the diaminopimelate and α-aminoadipate pathways, which employ distinct e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homocitrate Synthase
In enzymology, a homocitrate synthase () is an enzyme that catalyzes the chemical reaction :acetyl-CoA + H2O + 2-oxoglutarate \rightleftharpoons (R)-2-hydroxybutane-1,2,4-tricarboxylate + CoA The 3 substrates of this enzyme are acetyl-CoA, H2O, and 2-oxoglutarate, whereas its two products are (R)-2-hydroxybutane-1,2,4-tricarboxylate and CoA. This enzyme belongs to the family of transferases, specifically those acyltransferases that convert acyl groups into alkyl groups on transfer. The systematic name of this enzyme class is acetyl-CoA:2-oxoglutarate C-acetyltransferase (thioester-hydrolysing, carboxymethyl forming). Other names in common use include 2-hydroxybutane-1,2,4-tricarboxylate 2-oxoglutarate-lyase, (CoA-acetylating), acetyl-coenzyme A:2-ketoglutarate C-acetyl transferase, and homocitrate synthetase. This enzyme participates in lysine biosynthesis and pyruvate metabolism Pyruvic acid (CH3COCOOH) is the simplest of the alpha-keto acids, with a carboxylic aci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homoaconitase
Homoaconitase may refer to: * Homoaconitate hydratase * Methanogen homoaconitase {{Short pages monitor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anion
An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convention. The net charge of an ion is not zero because its total number of electrons is unequal to its total number of protons. A cation is a positively charged ion with fewer electrons than protons while an anion is a negatively charged ion with more electrons than protons. Opposite electric charges are pulled towards one another by electrostatic force, so cations and anions attract each other and readily form ionic compounds. Ions consisting of only a single atom are termed atomic or monatomic ions, while two or more atoms form molecular ions or polyatomic ions. In the case of physical ionization in a fluid (gas or liquid), "ion pairs" are created by spontaneous molecule collisions, where each generated pair consists of a free electron and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salt (chemistry)
In chemistry, a salt is a chemical compound consisting of an ionic assembly of positively charged cations and negatively charged anions, which results in a compound with no net electric charge. A common example is table salt, with positively charged sodium ions and negatively charged chloride ions. The component ions in a salt compound can be either inorganic, such as chloride (Cl−), or organic, such as acetate (). Each ion can be either monatomic, such as fluoride (F−), or polyatomic, such as sulfate (). Types of salt Salts can be classified in a variety of ways. Salts that produce hydroxide ions when dissolved in water are called ''alkali salts'' and salts that produce hydrogen ions when dissolved in water are called ''acid salts''. ''Neutral salts'' are those salts that are neither acidic nor basic. Zwitterions contain an anionic and a cationic centre in the same molecule, but are not considered salts. Examples of zwitterions are amino acids, many metabolites, peptid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ester
In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides are fatty acid esters of glycerol; they are important in biology, being one of the main classes of lipids and comprising the bulk of animal fats and vegetable oils. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. They perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Polyesters are important plastics, with monomers linked by ester moieties. Phosphoesters form the backbone of DNA molecules. Nitrate esters, such as nitroglycerin, are known for their explosive properties. '' Nomenclature Etymology Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homoaconitic Acid
Homoaconitatic acid (homoaconitate) is related to aconitic acid but with one extra carbon. It is part of the α-aminoadipate pathway for lysine biosynthesis, where it is made from homocitrate by homoaconitase. It is converted to homoisocitrate by homoisocitrate dehydrogenase. See also * Homoisocitric acid Homoisocitric acid is an isomer of homocitric acid in which the hydroxyl is on the 2 position. It is an intermediate in the α-aminoadipate pathway of lysine biosynthesis where it is produced by homocitrate synthase and is a substrate for homo ... References Tricarboxylic acids {{organic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adipic Acid
Adipic acid or hexanedioic acid is the organic compound with the formula (CH2)4(COOH)2. From an industrial perspective, it is the most important dicarboxylic acid: about 2.5 billion kilograms of this white crystalline powder are produced annually, mainly as a precursor for the production of nylon. Adipic acid otherwise rarely occurs in nature, but it is known as manufactured E number food additive E355. Preparation and reactivity Adipic acid is produced from a mixture of cyclohexanone and cyclohexanol called KA oil, the abbreviation of ketone-alcohol oil. The KA oil is oxidized with nitric acid to give adipic acid, via a multistep pathway. Early in the reaction, the cyclohexanol is converted to the ketone, releasing nitrous acid: :HOC6H11 + HNO3 → OC(CH2)5 + HNO2 + H2O Among its many reactions, the cyclohexanone is nitrosated, setting the stage for the scission of the C-C bond: :HNO2 + HNO3 → NO+NO3− + H2O :OC6H10 + NO+ → OC6H9-2-NO + H+ Side products of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tricarboxylic Acids
A tricarboxylic acid is an organic carboxylic acid whose chemical structure contains three carboxyl functional groups (-COOH). The best-known example of a tricarboxylic acid is citric acid. Uses Citric acid cycle Citric acid, a type of tricarboxylic acid, is used in the citric acid cycle – also known as tricarboxylic acid (TCA) cycle or Krebs cycle – which is fundamental to all aerobic organisms. Examples See also * Citric acid cycle (tricarboxylic acid cycle) * Dicarboxylic acid * Mellitic acid Mellitic acid, also called graphitic acid or benzenehexacarboxylic acid, is an acid first discovered in 1799 by Martin Heinrich Klaproth in the mineral mellite (honeystone), which is the aluminium salt of the acid. It crystallizes in fine silky ne ... Literature *{{cite journal , title = The Tricarboxylic Acid Cycle, an Ancient Metabolic Network with a Novel Twist. , author = Ryan J. Mailloux, Robin Bériault, Joseph Lemire, Ranji Singh, Daniel R. Chénier, Robert D. Hamel, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
