Question

Amongst 38 ATP, 34 ATP are derived from

• A. HMP
• B. Krebs cycle
• C. Glycolosis
• D. Electron chain transport

Answer 1

The correct option is D Electron chain transport

Net energy production from aerobic respiration:

Glycolysis: 2 ATP

Krebs Cycle: 2 ATP

Electron Transport Phosphorylation: 34 ATP

Each NADH produced in glycolysis is worth 3 ATP (2 x 3 = 6). The NADH is worth 3 ATP, but it costs an ATP to transport the NADH into the mitochondria, so there is a net gain of 2 ATP for each NADH produced in glycolysis.

Plants are a bit more efficient and they don't have to spend 2 ATP to transport NADH into their mitochondria.

Each NADH produced in the conversion of pyruvate to acetyl CoA and Krebs cycle is worth 3 ATP (8 x 3 = 24).

Each FADH${}_2$ is worth 2 ATP (2 x 2 = 4).

Hence, 6 + 24 + 4 = 34.