How many cycles of cyclic and non-cyclic photophorylation would be required in order to generate enough energy for the production of one glocose molecule?

Options

A. 10 cyclic and 4 non-cyclic photophosphorylation
B. 6 cyclic and 6 non-cyclic photophosphorylation
C. 2 cyclic and 4 non-cyclic photophosphorylation
D. 8 cyclic and 1 non-cyclic photophosphorylation

Answer

To determine how many cycles of cyclic and non-cyclic photophosphorylation are required to produce one molecule of glucose (C6H12O6), we need to analyze the energy requirements for glucose synthesis and the outputs of each type of photophosphorylation.

### Step-by-Step Solution:

1. **Understanding Glucose Production**:
- One molecule of glucose (C6H12O6) requires energy in the form of ATP and reducing power in the form of NADPH for its synthesis during photosynthesis.

2. **Cyclic Photophosphorylation**:
- In cyclic photophosphorylation, each cycle produces **2 ATP molecules**.
- To produce enough ATP for one glucose molecule, we need a total of **12 ATP molecules** (as 1 glucose molecule requires 12 ATP).
- Therefore, the number of cycles of cyclic photophosphorylation required can be calculated as follows:
\[ \text{Number of cycles} = \frac{\text{Total ATP required}}{\text{ATP produced per cycle}} = \frac{12}{2} = 6 \text{ cycles} \]

3. **Non-Cyclic Photophosphorylation**:
- In non-cyclic photophosphorylation, each cycle produces **1 ATP and 2 NADPH**.
- For glucose synthesis, we need **6 ATP** and **12 NADPH** (since 1 glucose requires 12 hydrogen ions, which corresponds to 12 NADPH).
- To meet the requirement of 12 NADPH, we need:
\[ \text{Number of cycles} = \frac{12 \text{ NADPH required}}{2 \text{ NADPH produced per cycle}} = 6 \text{ cycles} \]
- Each of these 6 cycles also produces 6 ATP (1 ATP per cycle).

4. **Total Cycles Required**:
- Thus, to produce one glucose molecule, we need:
- **6 cycles of cyclic photophosphorylation** (to produce 12 ATP)
- **6 cycles of non-cyclic photophosphorylation** (to produce 6 ATP and 12 NADPH)

5. **Final Conclusion**:
- Therefore, the total number of cycles required for the production of one glucose molecule is:
- **6 cycles of cyclic photophosphorylation**
- **6 cycles of non-cyclic photophosphorylation**

### Answer:
**6 cycles of cyclic photophosphorylation and 6 cycles of non-cyclic photophosphorylation are required to produce one glucose molecule.**

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