Question

Assertion (A) Two turns of Krebs' cycle occur per glucose molecule used.
Reason (R) Each turn of Krebs' cycle produces $3 NADH , 1 FADH _{2}$ and $1 ATP$ molecule.

• A. If both A and R are true and R is the correct explanation of A
• B. If both A and R are true, but R is not the correct explanation of A
• C. If A is true, but R is false
• D. If A is false, but R is true

Answer 1

Answer: (B)

Both Assertion and Reason are true, but Reason is not the correct explanation for Assertion.
Glucose is converted into two molecules of pyruvic acid due to which two Krebs' cycle occur for glucose molecule. Each turn of Krebs' cycle produces $3 \,NADH$, $1 \,FADH _{2}$ and $1 \, ATP$ molecules. On oxidation, $1 \,NADH$ produces $3 \, ATP$ molecules and $1 \, FADH _{2}$ produces $2 \, ATP$ molecules. In each turn of Krebs' cycle, $12 \, ATP$ molecules are produced.