Acetyl CoA is the link between carbohydrate and fat metabolism. In carbohydrate metabolism, during glycolysis, one molecule of hexose is broken down into two molecules of pyruvic acid. The pyruvic acid molecules are oxidatively decarboxylated into acetyl CoA, which is fed into Krebs cycle. For oxidation of fats, the long chains of fatty acids are converted into many acetyl CoA units by sequential removal of two carbon atoms at a time. These units of acetyl CoA are then fed into the usual Krebs cycle.