Photooxidation is

Options

A. Photorespiration
B. Photolysis
C. Light and oxygen induced break down
D. All the above.

Answer

**Step-by-Step Solution:**

1. **Understanding Photooxidation**: Photooxidation refers to a process where light energy causes the oxidation of a substance. In the context of photosynthesis, it specifically relates to the oxidation of chlorophyll.

2. **Identifying the Process**: The process of photooxidation is closely associated with photolysis, which is the splitting of water molecules (H2O) in the presence of light. This is a crucial step in photosynthesis that occurs in the chloroplasts.

3. **Mechanism of Photolysis**: During photolysis, chlorophyll absorbs light energy, which excites electrons in the chlorophyll molecule. This energy causes the chlorophyll to lose electrons, leading to its oxidation. The lost electrons are replaced by electrons derived from the splitting of water molecules.

4. **Role of Water**: The water molecules are split into oxygen, protons, and electrons. The oxygen is released as a byproduct into the atmosphere, while the electrons are used to replenish the chlorophyll.

5. **Location of the Process**: Photolysis occurs in the thylakoid membranes of the chloroplasts, specifically in the grana, which are stacks of thylakoids.

6. **Conclusion**: Therefore, the correct answer to the question "Photooxidation is" is photolysis. It is not photorespiration (which is a different process) or simply the breakdown of light and oxygen.

**Final Answer**: Photooxidation is photolysis.

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