Question

Net gain of ATP molecules, during aerobic respiration, is

• A. 40 molecules
• B. 48 molecules
• C. 36 molecules
• D. 38 molecules.

Answer 1

Answer: (D)

In aerobic respiration complete oxidation of one glucose molecule produces 38 ATP molecules. But the
number of ATP molecules so produced may vary depending upon the mode of entry of NADH 2 in the
mitochondria. If the electrons of NADH 2 are accepted by malate then each molecule of NADH 2 yields 3 ATP molecules and the total would be 38 ATP molecules. But if the electrons of NADH 2 are accepted by FAD it yields only 2 ATP molecules making the total of 36 ATP molecules. This type of shuttle occurs in most of the eukaryotic cells.