In aerobic cellular respiration, which process produces the most ATP per molecule of glucose?

• A. Glycolysis
• B. Pyruvate oxidation (conversion of pyruvate to acetyl-CoA)
• C. Oxidative phosphorylation (electron transport chain and ATP synthase)
• D. Citric acid cycle (Krebs cycle)

Answer: (C)

Verified step by step guidance

1. Understand the overall process of aerobic cellular respiration, which includes glycolysis, pyruvate oxidation, the citric acid cycle, and oxidative phosphorylation.
2. Recall that glycolysis produces a small amount of ATP directly by substrate-level phosphorylation and generates NADH for later use.
3. Recognize that pyruvate oxidation itself does not produce ATP directly but generates NADH, which feeds into the electron transport chain.
4. Know that the citric acid cycle produces some ATP (or GTP) directly and generates multiple NADH and FADH2 molecules, which carry electrons to the electron transport chain.
5. Identify that oxidative phosphorylation, which includes the electron transport chain and ATP synthase, uses the NADH and FADH2 produced in earlier steps to generate the majority of ATP through chemiosmosis, making it the process that produces the most ATP per glucose molecule.