How many molecules of glycine are required to release one molecule of `CO_(2)` in photorespiration

Options

A. One
B. Two
C. Three
D. Four.

Answer

To determine how many molecules of glycine are required to release one molecule of CO2 during photorespiration, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Photorespiration**:
- Photorespiration is a metabolic process in plants that occurs when the enzyme ribulose bisphosphate carboxylase/oxygenase (rubisco) binds with oxygen instead of carbon dioxide. This leads to the formation of phosphoglycolate instead of 3-phosphoglycerate.

2. **Location of Photorespiration**:
- The process occurs in three organelles: chloroplasts, peroxisomes, and mitochondria.

3. **Formation of Glycine**:
- During photorespiration, phosphoglycolate is converted into glycine. This process involves the conversion of two molecules of phosphoglycolate into two molecules of glycine.

4. **Release of CO2**:
- In the mitochondria, two molecules of glycine combine to form serine, releasing one molecule of CO2 in the process.

5. **Conclusion**:
- Therefore, to release one molecule of CO2, two molecules of glycine are required.

### Final Answer:
**2 molecules of glycine are required to release one molecule of CO2 during photorespiration.**