Secondary acceptor of `CO_(2)` in `C_(4)` plants is

Options

A. PEP
B. RUBP
C. PGAL
D. Rubisco

Answer

To determine the secondary acceptor of CO2 in C4 plants, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding C4 Photosynthesis**:
- C4 plants utilize a different pathway for photosynthesis compared to C3 plants. In C4 photosynthesis, CO2 is initially fixed in the mesophyll cells.

2. **Primary and Secondary Acceptors**:
- In C4 plants, the primary acceptor of CO2 is phosphoenolpyruvate (PEP), which combines with CO2 to form oxaloacetate.
- The secondary acceptor comes into play during the next steps of the C4 pathway.

3. **Role of RuBP**:
- RuBP (ribulose bisphosphate) is a crucial molecule in the Calvin cycle, which occurs in the bundle sheath cells of C4 plants.
- After the initial fixation of CO2, the oxaloacetate is converted to malate, which is then transported to the bundle sheath cells where it releases CO2.

4. **Final Conclusion**:
- In the bundle sheath cells, the released CO2 is then fixed by RuBP during the Calvin cycle. Therefore, RuBP acts as the secondary acceptor of CO2 in C4 plants.

5. **Answer Selection**:
- Based on the explanation, the correct answer to the question is that the secondary acceptor of CO2 in C4 plants is RuBP.

### Final Answer:
- The secondary acceptor of CO2 in C4 plants is **RuBP**.

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