The first stable product in `CAM//C_(4)` plants is

Options

A. Oxalic acid
B. Malic acid
C. Oxalo-acetic acid
D. Pyruvic acid

Answer

To solve the question regarding the first stable product in CAM (Crassulacean Acid Metabolism) and C4 plants, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding CAM and C4 Plants**:
- CAM and C4 plants are types of photosynthetic plants that have adapted to efficiently fix carbon dioxide (CO2) in conditions where it may be limited, such as in hot and dry environments.

2. **Identifying the Primary Acceptors**:
- In both CAM and C4 plants, the primary carbon dioxide acceptor is phosphoenolpyruvate (PEP), which is a three-carbon compound.

3. **Carbon Fixation Process**:
- When CO2 is fixed, PEP combines with CO2 to form a four-carbon compound. This reaction is catalyzed by the enzyme PEP carboxylase.

4. **Formation of the First Stable Product**:
- The first stable product formed after the fixation of CO2 with PEP is oxaloacetic acid (OAA), which is a four-carbon compound.

5. **Conclusion**:
- Therefore, the first stable product in CAM and C4 plants is oxaloacetic acid.

### Final Answer:
The first stable product in CAM and C4 plants is **oxaloacetic acid**.

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