Question

During which stage in the complete oxidation of glucose is the greatest number of ATP molecules produced from ADP?

• A. Glycolysis
• B. Kreb's cycle
• C. Decarboxylation
• D. ETS

Answer 1

Answer: (D)

Total NADH entering ETS is 10 (2 NADH from glycolysis, 2 NADH from link reaction, 6 NADH from Krebs' cycle. ATP formed from 1 NADH is 3. Thus ATP formed from 10 NADH is 30.
Total FADH2 entering ETS is 2 (from Krebs' cycle). ATP formed from 1 $FAD{H}_2$ is 2. Thus, ATP formed from 2 $FAD{H}_2$ is 4. Thus the ATP formed in ETS is 34 out of the total 38 produced by complete aerobic respiration of one molecule of glucose