Correct option is D
The correct answer is (d) Both (A) and (R) are true, and (R) is the correct explanation of (A)
Explanation:
- Assertion (A) is true: While glycolysis and the TCA cycle produce some ATP directly, about 90% of the ATP in aerobic respiration is generated in the final stage.
- Reason (R) is true: The Electron Transport Chain (ETC) pumps protons into the intermembrane space.
- The resulting proton motive force drives protons back through ATP synthase.
- This process of using a proton gradient to synthesize ATP is known as chemiosmosis, proposed by Peter Mitchell.
- Since R describes exactly how the ATP mentioned in A is produced, it is the correct explanation.
Information Booster:
- The inner mitochondrial membrane is folded into cristae to increase surface area for these reactions.
- One molecule of NADH produces approximately 2.5 ATP, and one FADH2 produces 1.5 ATP.
Additional Knowledge:
A is false, R is true (Option a)
- Incorrect; A is a fundamental concept of cellular biology.
Both true, R not explanation (Option b)
- Incorrect; the mechanism in R is the direct cause of the efficiency noted in A.
A is true, R is false (Option c)
- Incorrect; R accurately describes the Chemiosmotic Hypothesis.
So the correct answer is (d)
English
25 Questions
100 Marks
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