The number of ATP required in mesophyll cells of `C_(3)` plants and bundle sheath cells of `C_(4)` plants respecitvely for next export of 12G-3-P during dark reaction

Options

A. 108 and 180
B. 18 and 30
C. 18 and 18
D. 108 and 108

Answer

To determine the number of ATP molecules required for the export of 12 G3P (glyceraldehyde 3-phosphate) during the dark reactions in C3 and C4 plants, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding G3P Production in C3 Plants**:
- In C3 plants, the Calvin cycle is responsible for the production of G3P.
- It is known that to produce one molecule of G3P, a total of 9 ATP molecules are required.

2. **Calculating ATP for 12 G3P in C3 Plants**:
- Since 9 ATP are needed for 1 G3P, for 12 G3P, we multiply:
\[ \text{ATP required} = 12 \times 9 = 108 \text{ ATP} \]

3. **Understanding G3P Production in C4 Plants**:
- C4 plants also produce G3P through a similar process, but they have an additional step in their pathway.
- Similar to C3 plants, 9 ATP are required to produce 1 G3P.

4. **Calculating ATP for 12 G3P in C4 Plants**:
- Again, for 12 G3P, we perform the same multiplication:
\[ \text{ATP required} = 12 \times 9 = 108 \text{ ATP} \]

5. **Conclusion**:
- Therefore, the number of ATP required in mesophyll cells of C3 plants and bundle sheath cells of C4 plants for the export of 12 G3P is:
\[ \text{C3 Plants: } 108 \text{ ATP} \quad \text{C4 Plants: } 108 \text{ ATP} \]

### Final Answer:
Both C3 and C4 plants require 108 ATP for the export of 12 G3P.

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