during the Krebs cycle, the two carbon atoms of acetyl-CoA are released, and each forms a carbon dioxide molecule. ... At the end of the Krebs cycle, the final product is oxaloacetic acid.
Because for each glucose molecule there are two pyruvic acid molecules entering the system, two ATP molecules are formed. Also during the Krebs cycle, the two carbon atoms of acetyl-CoA are released, and each forms a carbon dioxide molecule.