Which one of the following enzymes of respiratory pathway has the coenzyme FAD hnked with it?

Answer

**Step-by-Step Solution:**

1. **Identify the Enzymes**: The question asks which enzyme in the respiratory pathway has FAD as a coenzyme. The options provided are:
- Citric acid synthetase
- Fumarase
- Succinic acid dehydrogenase

2. **Understand the Role of Each Enzyme**:
- **Citric Acid Synthetase**: This enzyme catalyzes the conversion of oxaloacetate and acetyl CoA into citrate. It does not involve FAD in its reaction.
- **Fumarase**: This enzyme catalyzes the conversion of fumarate to malate. This reaction also does not involve FAD.
- **Succinic Acid Dehydrogenase**: This enzyme catalyzes the conversion of succinate to fumarate. Importantly, this reaction generates FADH2, indicating that FAD is indeed a coenzyme linked with this enzyme.

3. **Conclusion**: After analyzing the roles of the enzymes, we can conclude that the enzyme that has FAD linked with it is **Succinic Acid Dehydrogenase**.

4. **Final Answer**: The correct answer is **Succinic Acid Dehydrogenase** (Option C).

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