Assertion : Oxidation of one molecule of NADH gives rise to 3 molecules of ATP and that of one molecule of `FADH_(2)` produces 2 molecules of ATP
Reason : The number of ATP molecules synthesised depends on the nature of the electron donor.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion
B. If both assertion and reason are true but reason is not the correct explanation of assertion
C. If assertion is true but reason is false
D. If both assertion and reason are false

Answer

**Step-by-Step Solution:**

1. **Understanding the Assertion**: The assertion states that the oxidation of one molecule of NADH results in the production of 3 molecules of ATP, while the oxidation of one molecule of FADH2 results in the production of 2 molecules of ATP. This is a factual statement based on the biochemical processes that occur during cellular respiration.

2. **Understanding the Reason**: The reason provided states that the number of ATP molecules synthesized depends on the nature of the electron donor. This means that different electron donors (like NADH and FADH2) contribute differently to ATP production based on their energy levels.

3. **Electron Donors**: NADH and FADH2 are both electron donors in the electron transport chain. NADH donates electrons at the beginning of the chain (Complex I), while FADH2 donates electrons at a later stage (Complex II).

4. **Energy Levels of Electrons**: The electrons from NADH are of higher energy compared to those from FADH2. This higher energy allows NADH to contribute to the production of more ATP (3 ATP molecules) compared to FADH2 (2 ATP molecules).

5. **Conclusion**: Both the assertion and the reason are correct. The assertion correctly states the ATP yield from NADH and FADH2, and the reason correctly explains why this difference exists based on the nature of the electron donors.

6. **Final Statement**: Therefore, both the assertion and the reason are correct, and the reason provides a correct explanation for the assertion.

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