 coenzyme a (coa, coash, or hscoa) is a coenzyme, notable for its role in the synthesis and oxidation of fatty acids, and the oxidation of pyruvate in the citric acid cycle. all genomes sequenced to date encode enzymes that use coenzyme a as a substrate, and around 4% of cellular enzymes use it (or a thioester, such as acetyl-coa) as a substrate. in humans, coa biosynthesis requires cysteamine, pantothenate, and adenosine triphosphate (atp). ==biosynthesis== in all living organisms, coenzyme a is synthesized in a five-step process that requires four molecules 
Coenzymes Metabolism Thiols