Question

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

• A. Glycolysis
• B. Krebs cycle
• C. Conversion of pyruvic acid to acetyl CoA
• D. Electron transport chain

Answer 1

Answer: (D)

Electron transport chain

Answer 2

The last step of aerobic respiration is the oxidation of reduced coenzymes, i.e.9 NADH2, and FADH2 by molecular oxygen through FAD, ubiquinone, Cyt b, Cyt c, Cyt cp Cyt a and Cyt a3 By oxidation of 1 molecule of NADH2, 3ATP molecules are produced and by oxidation of 1 molecule of FADH7, 2 ATP molecules are produced. In glycolysis 2 ATP molecules are produced from ADP. Further 2NADH2 produced, give 2x3 = 6 ATP, on oxidative phosphorylation. Similarly in Kreb's cycle 2 ATP molecules are produced. So the greatest number of ATP molecules are produced in the electron transport chain.