Photochemical reactions in the chloroplasts are directly involved in the

Options

A. Fixation of carbon dioxide
B. Synthesis of glucose and starch
C. Formation of phosphoglyceric starch
D. Photolysis of water and phosphorylation of ADP to ATP

Answer

**Step-by-Step Solution:**

1. **Understanding Photosynthesis**: Photosynthesis occurs in two main stages: photochemical (light-dependent) reactions and biochemical (light-independent) reactions.

2. **Identifying Photochemical Reactions**: Photochemical reactions take place in the chloroplasts and require light. They involve the absorption of light energy by chlorophyll.

3. **Processes in Photochemical Reactions**:
- **Photolysis of Water**: Light energy is used to split water (H2O) into hydrogen ions (H+), electrons, and oxygen (O2). This process is known as photolysis.
- **Formation of Energy Carriers**: The absorbed light energy is also used to convert ADP into ATP and to reduce NADP+ to NADPH. These two molecules (ATP and NADPH) are essential for the next stage of photosynthesis.

4. **Conclusion**: Therefore, the photochemical reactions in the chloroplasts are directly involved in the photolysis of water and the phosphorylation of ADP to ATP.

**Final Answer**: Photochemical reactions in the chloroplasts are directly involved in the photolysis of water and the phosphorylation of ADP to ATP.

---