In Kreb's cycle, the conversion of oxalosuccinate into `alpha`-ketoglutrate involves_____reaction.

Options

A. Oxidation
B. Reduction
C. Hydration
D. Decarboxylation

Answer

To solve the question regarding the conversion of oxalosuccinate into alpha-ketoglutarate in the Krebs cycle, we can break down the process step-by-step:

### 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 biochemical reactions that occur in the mitochondrial matrix. It plays a crucial role in cellular respiration.

2. **Identifying the Starting Compound**:
- The conversion in question starts with oxalosuccinate, which is a 6-carbon compound formed from isocitrate through a dehydrogenation reaction.

3. **Recognizing the Type of Reaction**:
- The conversion of oxalosuccinate to alpha-ketoglutarate involves the removal of a carboxyl group (CO2). This process is known as decarboxylation.

4. **Enzyme Involvement**:
- The enzyme that facilitates this decarboxylation reaction is oxalosuccinate decarboxylase. This enzyme catalyzes the removal of CO2 from oxalosuccinate.

5. **Formation of Alpha-Ketoglutarate**:
- After the decarboxylation reaction, the remaining 5-carbon compound is alpha-ketoglutarate, which is a key intermediate in the Krebs cycle.

6. **Conclusion**:
- Therefore, the conversion of oxalosuccinate into alpha-ketoglutarate involves a decarboxylation reaction.

### Final Answer:
The conversion of oxalosuccinate into alpha-ketoglutarate involves **decarboxylation**.

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