AAMC FL Practice Exam

How many ATP molecules are produced through aerobic respiration of one glucose molecule?

1. 2 ATP

2. 18 ATP

3. 36 ATP

4. 38 ATP

The correct answer is: 38 ATP

The correct answer indicates that 38 ATP molecules can be produced through the aerobic respiration of one glucose molecule when considering the theoretical maximum yield. Aerobic respiration involves several key stages, including glycolysis, the citric acid cycle, and oxidative phosphorylation. In glycolysis, which occurs in the cytoplasm, a net gain of 2 ATP molecules is generated. Next, during the citric acid cycle in the mitochondria, each glucose molecule (which is converted into two molecules of acetyl-CoA) contributes to the production of additional ATP and electron carriers, specifically 2 ATP, 6 NADH, and 2 FADH2. Each NADH produced can yield approximately 2.5 ATP when it donates electrons to the electron transport chain, while each FADH2 can yield about 1.5 ATP. When adding it all together: - From glycolysis: 2 ATP - From the citric acid cycle: 2 ATP - From NADH (6 molecules): 6 NADH x 2.5 ATP = 15 ATP - From FADH2 (2 molecules): 2 FADH2 x 1.5 ATP = 3 ATP Thus, the total ATP