In green plants, during photosynthesis water act as:

Options

A. Hydrogen acceptor
B. Oxygen acceptor
C. Hydrogen donor
D. Electron acceptor

Answer

To answer the question "In green plants, during photosynthesis, water acts as:", we can break down the process of photosynthesis and the role of water step by step.

### Step-by-Step Solution:

1. **Understanding Photosynthesis**:
- Photosynthesis is the process by which green plants convert light energy into chemical energy in the form of glucose. This process takes place mainly in the chloroplasts of plant cells.

2. **Light Reactions and Dark Reactions**:
- Photosynthesis consists of two main stages: light reactions and dark reactions (Calvin cycle). The light reactions occur in the thylakoid membranes and convert light energy into chemical energy (ATP and NADPH).

3. **Role of Water in Light Reactions**:
- During the light reactions, water (H₂O) is split in a process known as photolysis. This occurs in Photosystem II (PSII).

4. **Products of Water Splitting**:
- The splitting of water produces three main components:
- **Hydrogen ions (H⁺)**: These are released into the thylakoid lumen.
- **Electrons (e⁻)**: These replace the electrons lost by chlorophyll in PSII.
- **Oxygen (O₂)**: This is released as a by-product into the atmosphere.

5. **Function of Water**:
- Water acts as a **hydrogen donor** during photosynthesis. The hydrogen ions produced from the splitting of water are used to reduce NADP⁺ to NADPH, which is essential for the dark reactions.

6. **Conclusion**:
- Therefore, in green plants during photosynthesis, water primarily acts as a **hydrogen donor**.

### Final Answer:
Water acts as a **hydrogen donor** during photosynthesis in green plants.

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