Question: how many carbon atoms are fed into the citric acid cycle by pyruvate?
Answer: In the presence of oxygen, the three-carbon compound pyruvate can be catabolized in the citric acid cycle. First, however, the pyruvate 1) loses a carbon, which is given off as a molecule of CO2, 2) is oxidized to form a two- carbon compound called acetate, and 3) is bonded to coenzyme A.