`PEP`, the first `CO_(2)` acceptor in `C_(4)` cycle is

Options

A. 3-C compound
B. 4- C compound
C. 5- C compound
D. 6-C compound.

Answer

To solve the question regarding the first CO₂ acceptor in the C₄ cycle, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the C₄ Cycle**: The C₄ cycle, also known as the Hatch-Slack pathway, is a photosynthetic process that occurs in certain plants, allowing them to efficiently fix carbon dioxide.

2. **Identifying the First CO₂ Acceptor**: In the C₄ cycle, the first molecule that accepts carbon dioxide (CO₂) is crucial for the process.

3. **Recognizing Phosphoenolpyruvate (PEP)**: The molecule that acts as the first CO₂ acceptor in the C₄ cycle is phosphoenolpyruvate (PEP).

4. **Structure of PEP**: PEP is a 3-carbon compound. It consists of three carbon atoms in its structure.

5. **Formation of Oxaloacetic Acid**: When PEP combines with CO₂, it forms a 4-carbon compound called oxaloacetic acid (OAA). This reaction is catalyzed by the enzyme PEP carboxylase.

6. **Conclusion**: Since PEP is a 3-carbon compound and it is the first CO₂ acceptor in the C₄ cycle, the correct answer to the question is that PEP is a 3-carbon compound.

### Final Answer:
The first CO₂ acceptor in the C₄ cycle, PEP, is a **3-carbon compound**.

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