How much assimilatory power is required to form one glucose in a `C_3` plant

Options

A. 18 ATP - 12NADPH ` +H^(+)`
B. 30 ATP - 12NADPH ` +H^(+)`
C. 24 ATP - 18NADPH ` +H^(+)`
D. 30 ATP - 18NADPH ` +H^(+)`

Answer

To determine how much assimilatory power is required to form one glucose molecule in a C3 plant, we need to analyze the photosynthesis process, particularly focusing on the Calvin cycle.

### Step-by-Step Solution:

1. **Understanding Photosynthesis in C3 Plants**:
- Photosynthesis is a process where carbon dioxide is reduced to form carbohydrates (like glucose). This process requires energy and reducing power, which are provided by ATP and NADPH.

2. **Calvin Cycle Overview**:
- In C3 plants, the Calvin cycle is the pathway through which carbon dioxide is fixed into organic molecules. To synthesize one glucose molecule, the Calvin cycle must turn six times.

3. **ATP and NADPH Requirements per Turn**:
- Each turn of the Calvin cycle requires:
- 3 ATP molecules
- 2 NADPH molecules

4. **Calculating Total Requirements for One Glucose**:
- Since one glucose molecule requires six turns of the Calvin cycle:
- Total ATP required = 6 turns × 3 ATP/turn = 18 ATP
- Total NADPH required = 6 turns × 2 NADPH/turn = 12 NADPH

5. **Conclusion**:
- Therefore, to form one glucose molecule in a C3 plant, a total of 18 ATP and 12 NADPH are required.

### Final Answer:
- The assimilatory power required to form one glucose in a C3 plant is **18 ATP and 12 NADPH**.