Coenzyme A (CoA, CoASH, or HSCoA) is adapted from pantothenic acid and adenosine triphosphate and used in metabolism in areas such as fatty acid oxidization and the citric acid cycle. Its main function is to carry acyl groups such as acetyl as thioesters. A molecule of coenzyme A carrying an acetyl group is also referred to as acetyl-CoA.

Acetyl-CoA is an important molecule itself. It is the precursor to HMG CoA, which is a vital component in cholesterol and ketone synthesis. Furthermore, it contributes the acetyl group to acetylcholine; the addition of the acetyl group to choline a reaction that is catalysed by choline acetyltransferase. It's main task is conveying the carbon atoms within the acetyl group to the citric acid cycle to be oxidized for energy production.

See also

• Citric acid cycle
• HMG-CoA reductase pathway