Two molecules of the primary acceptor of carbon dioxide in Calvin cycle undergoes photorespiration. How many glycine molecules will be formed from it ?

Options

A. 1
B. 2
C. 3
D. 4

Answer

To solve the question, we need to understand the process of photorespiration and how it relates to the formation of glycine molecules from the primary acceptor of carbon dioxide in the Calvin cycle.

### Step-by-Step Solution:

1. **Identify the Primary Acceptor of CO2**:
- The primary acceptor of carbon dioxide in the Calvin cycle is Ribulose bisphosphate (RuBP).

2. **Understand Photorespiration**:
- Photorespiration is a process that occurs when the enzyme RuBisCO reacts with oxygen instead of carbon dioxide, leading to the production of a two-carbon compound, which is then converted into glycine.

3. **Conversion of Compounds**:
- During photorespiration, RuBP reacts with oxygen to produce 3-phosphoglycerate (3-PGA) and a two-carbon compound. This two-carbon compound is converted into glycine.

4. **Formation of Glycine**:
- For every two molecules of the primary acceptor (RuBP) that undergo photorespiration, two molecules of glycine are formed. This is because each molecule of the two-carbon compound produced during photorespiration can be converted into one molecule of glycine.

5. **Final Calculation**:
- Since we have two molecules of RuBP undergoing photorespiration, we will end up with two molecules of glycine.

### Conclusion:
Thus, the number of glycine molecules formed from two molecules of the primary acceptor of carbon dioxide in the Calvin cycle undergoing photorespiration is **2**.