Acetyl coenzyme A or acetyl-CoA is an important molecule in metabolism, used in many biochemical reactions. Its main function is to convey the carbon atoms within the acetyl group to the citric acid cycle (Krebs cycle) to be oxidized for energy production. Structure of  coenzyme A (CoASH or CoA) consists of a ß-mercaptoethylamine group linked to the vitamin pantothenic acid through an amide linkage. The acetyl group of acetyl-CoA is linked by a "high energy" thioester to the sulfhydryl portion of the ß-mercaptoethylamine. It is this thioester bond that makes acetyl-CoA one of the "high energy" compounds. Hydrolysis of the thioester bond is highly exergonic (-31.5 kJ). Acetyl-CoA is produced during breakdown of carbohydrates through glycolysis as well as fatty acid oxidation and enters the citric acid cycle.