Final answer:
Pyruvate dehydrogenase converts pyruvate into acetyl CoA through the removal of a carboxyl group and oxidation of a hydroxyethyl group.
Step-by-step explanation:
Pyruvate dehydrogenase is an enzyme that is responsible for the conversion of pyruvate, a molecule produced during glycolysis, into acetyl CoA. This reaction is a critical step in cellular respiration and occurs in the mitochondrial matrix. Pyruvate dehydrogenase removes a carboxyl group from pyruvate, producing carbon dioxide, and oxidizes a hydroxyethyl group to an acetyl group, producing NADH. Lastly, an enzyme-bound acetyl group is transferred to CoA, producing a molecule of acetyl-CoA.