Before pyruvate oxidation, pyruvate must be produced through the process of glycolysis in the cytoplasm of the cell. During glycolysis, glucose, a six-carbon molecule, is broken down into pyruvate, a three-carbon molecule. This process releases a small amount of energy in the form of ATP and NADH. After the pyruvate is produced, it is transported from the cytoplasm into the mitochondria, where pyruvate oxidation occurs. Before pyruvate can be oxidized, it must first be converted into acetyl-CoA through a series of reactions that remove a carbon dioxide molecule from each pyruvate molecule and transfer the remaining two-carbon fragment to Coenzyme A (CoA). The resulting acetyl-CoA can then enter the Krebs cycle, also known as the citric acid cycle, where it is further oxidized to generate more ATP and reduce electron carriers.