Hydration reaction occurs in Krebs cycle during conversion of

Options

A. Acetyl CoA to citric acid
B. `alpha`-ketoglutrate to succinyl CoA
C. Succinate to fumarate
D. Fumarate to malate

Answer

**Step-by-Step Solution:**

1. **Understanding the Krebs Cycle:**
The Krebs cycle, also known as the citric acid cycle or TCA cycle, is a series of chemical reactions used by all aerobic organisms to generate energy through the oxidation of acetate derived from carbohydrates, fats, and proteins.

2. **Identifying Hydration Reactions:**
In the Krebs cycle, hydration reactions involve the addition of water (H2O) to a substrate. There are two key hydration reactions in the cycle.

3. **First Hydration Reaction:**
The first hydration reaction occurs during the conversion of **cis-aconitate to isocitrate**. This reaction is catalyzed by the enzyme **aconitase**.

4. **Second Hydration Reaction:**
The second hydration reaction occurs in the conversion of **fumarate to malate**. This reaction is catalyzed by the enzyme **fumarase** and involves the addition of water (H2O).

5. **Conclusion:**
Among the options provided, the hydration reaction that occurs in the Krebs cycle is specifically during the conversion of **fumarate to malate**.

**Final Answer:**
The hydration reaction occurs in the Krebs cycle during the conversion of **fumarate to malate**.

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