acetyl coenzyme A (acetyl CoA) A compound formed in the mitochondria when an acetyl group (CH₃CO–), derived from the breakdown of fats, proteins, or carbohydrates (via glycolysis), combines with the thiol group (–SH) of coenzyme A. Acetyl CoA feeds into the energy generating the Krebs cycle and also plays a role in the synthesis and oxidation of fatty acids.

acetyl coenzyme A (acetyl Co A) An important intermediate in the citric-acid cycle, and in fatty-acid and amino-acid metabolism.