During light reaction of photosynthesis the electrons lost by pigment system II are compensated by

Options

A. `CO_(2)`
B. `H_(2)O`
C. `O_(2)`
D. ATP

Answer

**Step-by-Step Solution:**

1. **Understanding Light Reactions**: The light reactions of photosynthesis occur in the presence of light and involve two main pigment systems: Photosystem II (PSII) and Photosystem I (PSI). These reactions are crucial for converting light energy into chemical energy.

2. **Role of Photosystem II**: In Photosystem II, light energy is absorbed, which excites electrons. These electrons are then transferred through a series of proteins in the thylakoid membrane, known as the electron transport chain.

3. **Electron Loss in PSII**: When the electrons are excited and leave Photosystem II, they need to be replaced to maintain the flow of the electron transport chain. This is where the compensation comes into play.

4. **Source of Compensating Electrons**: The electrons lost by Photosystem II are compensated by the process known as photolysis of water. During photolysis, water molecules (H2O) are split into oxygen (O2), protons (H+), and electrons (e-). The electrons released from this process are used to replace those lost by Photosystem II.

5. **Conclusion**: Therefore, the correct answer to the question is that the electrons lost by pigment system II are compensated by the photolysis of water.

**Final Answer**: The electrons lost by pigment system II are compensated by the photolysis of water.

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