When 12 `CO_(2)` molecules are utilized in `C_(3)` cycle, number of triose phosphates exported out from the chloroplast into the cystosol for the synthesis of hexose will be

Options

A. 2
B. 4
C. 6
D. 12

Answer

To solve the question of how many triose phosphates are exported out from the chloroplast into the cytosol for the synthesis of hexose when 12 CO₂ molecules are utilized in the C₃ cycle, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the C₃ Cycle**: The C₃ cycle, also known as the Calvin cycle, is the process by which plants convert carbon dioxide (CO₂) into glucose. The cycle begins with the fixation of CO₂ into ribulose bisphosphate (RuBP) by the enzyme RuBisCO.

2. **Formation of 3-Phosphoglycerate**: Each CO₂ molecule that enters the cycle results in the formation of 3-phosphoglycerate (3-PGA). Therefore, for every CO₂ molecule, one molecule of 3-PGA is produced.

3. **Reduction Phase**: The 3-PGA molecules are then reduced to form triose phosphates (TPs) using ATP and NADPH. For every 3-PGA molecule, one triose phosphate (specifically glyceraldehyde-3-phosphate, G3P) is produced.

4. **Calculating Triose Phosphate Production**: Since 12 CO₂ molecules are utilized, and each CO₂ molecule produces one triose phosphate, the total number of triose phosphates produced will be equal to the number of CO₂ molecules. Therefore, from 12 CO₂ molecules, 12 triose phosphates are produced.

5. **Exporting Triose Phosphates**: In the context of the synthesis of hexose sugars (like glucose), it is important to note that not all triose phosphates produced are exported. Typically, only a fraction of the triose phosphates are exported to the cytosol for the synthesis of hexose sugars. However, the question asks for the total number of triose phosphates produced, which is 12.

6. **Final Answer**: The number of triose phosphates exported out from the chloroplast into the cytosol for the synthesis of hexose will be **12**.

### Summary:
When 12 CO₂ molecules are utilized in the C₃ cycle, **12 triose phosphates** are produced and can be exported for hexose synthesis.