How many molecules of inorganic phosphate are released in Calvin cycle in formation of one glucose ?

Options

A. 12
B. 16
C. 17
D. 18

Answer

To determine how many molecules of inorganic phosphate are released in the Calvin cycle during the formation 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 occur in the stroma of chloroplasts in photosynthetic organisms. It is responsible for converting carbon dioxide and other compounds into glucose.

2. **Identify the Inputs and Outputs**: The Calvin cycle uses ATP and NADPH produced in the light-dependent reactions of photosynthesis to convert carbon dioxide into glucose. The main products of the Calvin cycle are glucose and inorganic phosphate.

3. **Determine the Number of Turns of the Calvin Cycle**: To produce one molecule of glucose (C6H12O6), the Calvin cycle must turn six times. This is because each turn of the cycle fixes one carbon atom from carbon dioxide, and glucose contains six carbon atoms.

4. **Calculate the Phosphate Released**: Each turn of the Calvin cycle involves the regeneration of ribulose bisphosphate (RuBP) and releases one molecule of inorganic phosphate (Pi). Therefore, for six turns of the cycle (to produce one glucose), a total of 6 inorganic phosphate molecules are released.

5. **Consider the Total Requirement for Glucose Formation**: However, to fully synthesize one glucose molecule, additional phosphate groups are needed for the formation of intermediates and for the regeneration of RuBP. This leads to a total release of 12 inorganic phosphate molecules during the entire process of glucose synthesis.

6. **Final Answer**: Therefore, the total number of inorganic phosphate molecules released in the Calvin cycle for the formation of one glucose molecule is **12**.

### Final Answer:
**12 molecules of inorganic phosphate are released in the Calvin cycle during the formation of one glucose.**

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