The citric acid cycle catalyzes the complete oxidation of the carbon atoms in acetyl CoA. The reaction of acetyl CoA with oxaloacetate starts the cycle by producing citrate (citric acid). Each turn of the cycle produces two molecules of CO₂ (as waste products), three molecules of NADH, one molecule of GTP, and one molecule of FADH₂. The number of carbon atoms in each intermediate is shown in a yellow box. (See also Simplified Diagram of Cellular Metabolism)  Fair Use and Copyright info