The over all reaction of the Calvin cycle is

Options

A. `3RUBR +3 CO_(2) + 9 ATP + 6 NADPH + H^(+) rarr 3PGA + 9 ADP + 9Pi +6NADP^(+)`
B. `3RUBR +3CO_(2) + 6 ATP + 6 NADPH + H^(+) rarr 3PGA + 6 ADP + 6Pi +6NADP^(+)`
C. `3RUBR +3 CO_(2) + 9 ATP + 6 NADPH + H^(+) rarr 6 G - 3P + 9 ADP + 6 NADP^(+) + 9Pi`
D. `3RUBR +3 CO_(2) + 6 ATP + 6 NADPH + H^(+) rarr 6 G - 3P + 6 ADP + 6 NADP^(+) + 5Pi`

Answer

To determine the overall reaction of the Calvin cycle, we need to understand the inputs and outputs of the cycle. Here’s a step-by-step breakdown of the overall reaction:

### Step 1: Identify the Main Components
The Calvin cycle primarily involves the following components:
- **Ribulose bisphosphate (RuBP)**: A 5-carbon sugar that reacts with CO2.
- **Carbon dioxide (CO2)**: The source of carbon for the synthesis of glucose.
- **ATP and NADPH**: Energy and reducing power generated from the light-dependent reactions of photosynthesis.

### Step 2: Write the Basic Reaction
The basic reaction of the Calvin cycle can be summarized as:
\[ 3 \text{RuBP} + 3 \text{CO}_2 + 6 \text{NADPH} + 6 \text{H}^+ + 9 \text{ATP} \rightarrow 6 \text{G3P} + 6 \text{NADP}^+ + 9 \text{ADP} + 8 \text{Pi} \]
Where G3P (glyceraldehyde-3-phosphate) is the primary product of the cycle.

### Step 3: Analyze the Options
Now, we need to compare this reaction with the provided options:
1. **Option 1**: 3RuBP + 3CO2 + 9ATP + 6NADPH + H+ → 3PGA + 9ADP + 6NADP+
2. **Option 2**: 3RuBP + 3CO2 + 6ATP + 6NADPH + H+ → 6PGA + 6NADPH + 3RuBP + 3CO2 + 9ATP + 6NADPH + H+ → 6G3P + 9ADP + 6NADP+
3. **Option 3**: 3RuBP + 3CO2 + 6ATP + 6NADPH + H+ → 6G3P + 9ADP + 6NADP+
4. **Option 4**: 3RuBP + 3CO2 + 6ATP + 6NADPH + H+ → 6G3P + 9ADP + 6NADP+

### Step 4: Determine the Correct Option
From the analysis, we can see that:
- The correct overall reaction of the Calvin cycle produces G3P, NADP+, ADP, and Pi.
- The only option that matches the overall reaction with the correct stoichiometry is **Option 3**.

### Conclusion
Thus, the overall reaction of the Calvin cycle is:
\[ 3 \text{RuBP} + 3 \text{CO}_2 + 6 \text{NADPH} + 9 \text{ATP} \rightarrow 6 \text{G3P} + 6 \text{NADP}^+ + 9 \text{ADP} + 8 \text{Pi} \]