Maximum energy can be obtained from oxidation of which respiratory substrate

Options

A. Fat
B. Proteins
C. Carbohydrates
D. Organic acid

Answer

**Step-by-Step Solution:**

1. **Identify the Respiratory Substrates:**
- The main respiratory substrates are carbohydrates, fats, and proteins. Each of these substrates can be oxidized to release energy.

2. **Energy Yield from Each Substrate:**
- Calculate the energy produced from the oxidation of each substrate:
- **Carbohydrates:** 1 gram of carbohydrates yields approximately 4 calories of energy.
- **Fats:** 1 gram of fats yields approximately 9 calories of energy.
- **Proteins:** 1 gram of proteins yields approximately 4 calories of energy.

3. **Comparison of Energy Yields:**
- Compare the energy yields:
- Carbohydrates: 4 calories/gram
- Fats: 9 calories/gram
- Proteins: 4 calories/gram
- From this comparison, it is evident that fats provide the highest amount of energy per gram.

4. **Conclusion:**
- Based on the energy yield from the oxidation of these substrates, the maximum energy can be obtained from the oxidation of fats.

5. **Final Answer:**
- The correct answer is **Option A: Fat**.

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