coenzyme Q

coenzyme /co·en·zyme/ (ko-en´zīm) an organic nonprotein molecule, frequently a phosphorylated derivative of a water-soluble vitamin, that binds with the protein molecule (apoenzyme) to form the active enzyme (holoenzyme).

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coenzyme A  a coenzyme containing among its constituents pantothenic acid and a terminal thiol group that forms high-energy thioester linkages with various acids, e.g., acetic acid (acetyl CoA) and fatty acids (acyl CoA); these thioesters play a central role in the tricarboxylic acid cycle, the transfer of acetyl groups, and the oxidation of fatty acids. Abbreviated CoA and CoA-SH.

coenzyme Q , coenzyme Q10 ubiquinone.

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coenzyme Q

n.

Ubiquinone.

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coenzyme Q (CoQ),

a designation for quinones with polymer side chains that mediate electron transfer between cytochrome beta and cytochrome c.

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coenzyme

an organic molecule, usually containing phosphorus and some vitamins, often separable from the enzyme protein but essential as a cosubstrate in catalysis; a coenzyme and an apoenzyme must unite in order to function (as a holoenzyme).

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coenzyme A

essential for carbohydrate and fat metabolism; among its constituents are pantothenic acid and a terminal SH group, which forms thioester linkages with various acids, e.g. acetic acid (acetyl-CoA) and fatty acids (acyl-CoA); abbreviated CoA.

coenzyme A acetoacetyl

see acetoacetyl coa.

coenzyme A acetyl

see acetyl coa.

coenzyme Q

any of a group of related quinones with isoprenoid units in the side chains (the ubiquinones), occurring in the lipid fraction of mitochondria and serving, along with the cytochromes, as an intermediate in electron transport; they are similar in structure to vitamin K₁.

coenzyme R

see biotin.