What is true for photosynthesis

Options

A. Both carbon dioxide and water are oxidised
B. Both carbon dioxide and water are reduced
C. carbon dioxide is oxidised and water reduced
D. Carbon dioxide is reduced and water oxidised

Answer

To determine what is true for photosynthesis, let's analyze the options provided in the question step by step.

### Step-by-Step Solution:

1. **Understanding Photosynthesis**:
- Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy into chemical energy in the form of glucose. This process primarily occurs in the chloroplasts of plant cells.

2. **Photosynthesis Equation**:
- The general equation for photosynthesis can be written as:
\[ 6 \text{CO}_2 + 6 \text{H}_2\text{O} + \text{light energy} \rightarrow \text{C}_6\text{H}_{12}\text{O}_6 + 6 \text{O}_2 \]
- Here, carbon dioxide (CO₂) and water (H₂O) are the reactants, and glucose (C₆H₁₂O₆) and oxygen (O₂) are the products.

3. **Identifying Oxidation and Reduction**:
- In the photosynthesis reaction:
- **Carbon Dioxide (CO₂)**: This molecule gains electrons (is reduced) to form glucose (C₆H₁₂O₆).
- **Water (H₂O)**: This molecule loses electrons (is oxidized) to produce oxygen (O₂).

4. **Evaluating the Options**:
- **Option 1**: Both carbon dioxide and water are oxidized. (Incorrect)
- **Option 2**: Both carbon dioxide and water are reduced. (Incorrect)
- **Option 3**: Both carbon dioxide is oxidized and water is reduced. (Incorrect)
- **Option 4**: Carbon dioxide is reduced and water is oxidized. (Correct)

5. **Conclusion**:
- The correct statement regarding photosynthesis is that carbon dioxide is reduced and water is oxidized. Therefore, the correct answer is **Option 4**.