The substrate for photorespiration is

Options

A. Glycolate
B. Glucose
C. Pyruvic acid
D. Acetyl COA

Answer

To determine the substrate for photorespiration, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Photorespiration**:
- Photorespiration is a process that occurs in plants where oxygen is consumed and carbon dioxide is released, leading to a wasteful reaction that does not produce useful energy or products.

2. **Identify the Sites of Photorespiration**:
- Photorespiration occurs primarily in the chloroplasts, but it can also take place in mitochondria and peroxisomes.

3. **Role of Rubisco**:
- The enzyme ribulose bisphosphate carboxylase/oxygenase (commonly known as Rubisco) plays a crucial role in photorespiration. It catalyzes the reaction between ribulose 1,5-bisphosphate (RuBP) and oxygen.

4. **Formation of Phosphoglycolate**:
- During the photorespiration process, Rubisco facilitates the oxygenation of RuBP, leading to the formation of a compound called phosphoglycolate.

5. **Dephosphorylation of Phosphoglycolate**:
- Phosphoglycolate undergoes dephosphorylation, which involves the removal of a phosphate group, resulting in the formation of glycolate.

6. **Identify the Substrate**:
- Glycolate is the first product formed in the photorespiration process and is considered the substrate for subsequent reactions in photorespiration.

### Conclusion:
The substrate for photorespiration is **glycolate**.

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