What are the outputs of the Prep Stage in cellular respiration?

• A. 2 Pyruvate, Acetyl CoA, CO2, 2 NADH
• B. Acetyl CoA, CO2, 2 ATP, 2 NADH
• C. Acetyl CoA, CO2, 4 ATP
• D. Pyruvate, CO2, 2 ATP, 2 NADH

Answer: (B)

The Prep Stage (pyruvate oxidation) converts each pyruvate from glycolysis into acetyl-CoA in the mitochondrial matrix, releasing carbon dioxide and producing NADH. For one glucose, two pyruvate molecules are processed, giving 2 acetyl-CoA, 2 CO2, and 2 NADH. No ATP is produced in this stage; ATP comes from glycolysis and later steps. So the outputs are acetyl-CoA, CO2, and NADH. Among the provided options, the one that reflects those products is closest, though it incorrectly includes ATP, which isn’t produced in this step.