For the synthesis of one glucose molecule the calvin cycle operates for:

Options

A. 2 times
B. 4 times
C. 6 times
D. 8 times

Answer

To determine how many times the Calvin cycle operates for the synthesis of one glucose molecule, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Calvin Cycle**: The Calvin cycle is a series of biochemical reactions that take place in the stroma of chloroplasts in photosynthetic organisms. It is responsible for fixing carbon dioxide and synthesizing glucose.

2. **Identify the Key Processes**: The Calvin cycle consists of three main stages:
- **Carboxylation**: The fixation of carbon dioxide.
- **Reduction**: The conversion of 3-phosphoglycerate (3-PGA) into glyceraldehyde-3-phosphate (G3P).
- **Regeneration**: The regeneration of ribulose bisphosphate (RuBP) to continue the cycle.

3. **Carbon Dioxide Fixation**: Each turn of the Calvin cycle fixes one molecule of carbon dioxide.

4. **Determine Carbon Requirement for Glucose**: A glucose molecule (C6H12O6) contains six carbon atoms. Therefore, to synthesize one glucose molecule, six carbon dioxide molecules must be fixed.

5. **Calculate the Number of Turns**: Since one turn of the Calvin cycle fixes one carbon dioxide molecule, to fix six carbon dioxide molecules, the Calvin cycle must operate six times.

6. **Conclusion**: Therefore, for the synthesis of one glucose molecule, the Calvin cycle operates **six times**.

### Final Answer:
The Calvin cycle operates **6 times** for the synthesis of one glucose molecule. The correct option is **C**.

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