coenzyme A

n. Abbr. CoA A coenzyme present in all living cells that transfers acetyl or acyl groups in metabolic reactions and that regulates gene expression through acetylation of histones.

coenzyme A

n (Biochemistry) a constituent of biological cells that functions as the agent of acylation in metabolic reactions. Abbreviation: CoA

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Noun

coenzyme A - a coenzyme present in all living cells; essential to metabolism of carbohydrates and fats and some amino acidscoenzyme - a small molecule (not a protein but sometimes a vitamin) essential for the activity of some enzymes

Coenzyme A

coenzyme A

[kō′en‚zīm ′ā] (biochemistry) C₂₁H₃₆O₁₆N₇P₃S A coenzyme in all living cells; required by certain condensing enzymes to act in acetyl or other acyl-group transfer and in fatty-acid metabolism. Abbreviated CoA.

Coenzyme A

(CoA), an acetylation (or acylation) coenzyme; the most important of the coenzymes.

Coenzyme A takes part in reactions involving the transfer of acyl groups. A molecule CoA consists of an adenylic acid radical (1) bonded by a pyrophosphate group (2) to a pantothenic acid radical (3) that is, in turn, linked by a peptide bond to (4) a β-mercaptoethanolamine radical (see Figure 1).

An extensive group of biochemical reactions involve CoA activity; these include the reactions at the basis of the oxidation and synthesis of fatty acids, the biosynthesis of lipids, and the oxidative conversions of the products of carbohydrate decomposition. In all cases, CoA acts as an intermediate compound, bonding the acid residues and transferring them to other substances. During this process, the acid residues either undergo

Figure 1. Coenzyme A

conversions in compounds with CoA or transfer without alteration to specific metabolites. Acyl radicals joined to the sulfhydryl (SH) group of CoA by a high-energy acylthioether bond are referred to as the active form of organic acids.

F. Lipmann, who isolated CoA from pigeon’s liver in 1947, and F. Lynen have been central in the investigation of the chemical structure and biological role of CoA. H. G. Khorana synthe-sized CoA completely in 1961.

IU. N. LEIKIN

coenzyme A

coenzyme

[ko-en´zīm] an organic molecule, usually containing phosphorus and some vitamins, sometimes separable from the enzyme protein; a coenzyme and an apoenzyme must unite in order to function (as a holoenzyme).coenzyme A a coenzyme essential for carbohydrate and fat metabolism; among its constituents are pantothenic acid and a terminal SH group, which forms linkages with various acids, e.g., acetic acid (acetyl CoA) and fatty acids (acyl CoA); abbreviated CoA.coenzyme Q any of a group of related quinones occurring in the lipid fraction of mitochondria and serving, along with the cytochromes, as an intermediate in electron transport; they are similar in structure and function to vitamin K₁.

co·en·zyme A (CoA),

(kō-en'zīm), A coenzyme containing pantothenic acid, adenosine 3'-phosphate 5'-pyrophosphate, and cysteamine; involved in the transfer of acyl groups, notably in transacetylations.

coenzyme A

n. Abbr. CoA A coenzyme present in all living cells that transfers acetyl or acyl groups in metabolic reactions and that regulates gene expression through acetylation of histones.

co·en·zyme A

(CoA) (kō-en'zīm) A coenzyme containing pantothenic acid, adenosine 3'-phosphate 5'-pyrophosphate, and cysteamine; involved in the transfer of acyl groups, notably in transacetylations.

coenzyme A

see ACETYLCOENZYME A.

coenzyme A

coenzyme A

coenzyme A

Coenzyme A

coenzyme A

Coenzyme A

coenzyme A

coenzyme

co·en·zyme A (CoA),

coenzyme A

co·en·zyme A

coenzyme A

coenzyme A

Words related to coenzyme A

noun a coenzyme present in all living cells

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