Question

The total number of ATP's formed when one molecule of glucose is oxidized to $C{O}_2$ to $H_{2}O$ is

• A. 32
• B. 38
• C. 42
• D. 40

Answer 1

Answer: (B)

38

One molecule of the glucose that enters in the glycolysis produces 2 molecules pyruvate and 2 molecules of NADH${}_2$ and 2 ATP. 2 molecules of pyruvate will form 2 molecules of Acetyl Co-A and this will release 2 NADH${}_2$. These 2 Acetyl Co-A will enter into Kreb's cycle and will release 6NADH${}_2$, 2FADH${}_2$ and 2ATP.

so, the total gain before the ETC (electron transport chain) comes out to be 10NADH${}_2$, 2FADH${}_2$ and 4ATP.

Now, during the electron transport chain,

10NADH${}_2$ will give 10 X 3=30 ATP

2FADH${}_2$ will give 2 X 2= 4 ATP

So, 34 ATP from ETC and 4 ATP from Kreb's cycle will be 38 ATP.

Hence, the correct answer is '38'