Which of the following chemical reac tions are associated with photorespiration?

Options

A. `Ru BP + O_(2) overset("RuBP oxygenese")to O _(2) PGA + `Phosphoglycolate
B. Glycolate `+ O_(2) overset("oxidase") to ` Glyoxylate `+ H _(2) O _(2)`
C. Glycerate `+ ATP overset("Kinase") to 2` phosphoglycerate + ADP
D. `RuBP + CO _(2) overset("RuBP") underset("Carboxylase") to 2 PGA`

Answer

To determine which chemical reactions are associated with photorespiration, we need to analyze the given reactions and understand the process of photorespiration itself.

### Step-by-Step Solution:

1. **Understanding Photorespiration**:
- Photorespiration is a process that occurs in higher plants where oxygen is consumed and carbon dioxide is released. It is often considered a wasteful pathway because it can lead to the loss of fixed carbon and energy.

2. **Analyzing the Reactions**:
- **Reaction 1**: Ribulose bisphosphate (RuBP) + O2 in the presence of Rubisco (ribulose bisphosphate carboxylase/oxygenase) produces phosphoglycerate (PGA) + phosphoglycolate.
- **Analysis**: This reaction is associated with photorespiration as it involves RuBP and oxygen, leading to the production of phosphoglycolate, which is a key intermediate in photorespiration.

- **Reaction 2**: Glycolate + O2 in the presence of oxidase produces glyoxylate + hydrogen peroxide.
- **Analysis**: This reaction occurs in the peroxisome and is also part of the photorespiration pathway. The formation of hydrogen peroxide is a by-product of this reaction.

- **Reaction 3**: Glycerate + ATP in the presence of kinase produces 2-phosphoglycerate + ADP.
- **Analysis**: This reaction is incorrect in the context of photorespiration. In photorespiration, ATP is not produced from glycerate; rather, it is consumed.

- **Reaction 4**: Ribulose bisphosphate (RuBP) + CO2 in the presence of Rubisco produces 2-phosphoglycerate.
- **Analysis**: This reaction is part of the Calvin cycle, not photorespiration. It involves the fixation of carbon dioxide, which is distinct from the photorespiration process.

3. **Conclusion**:
- The reactions associated with photorespiration are primarily the first and second reactions. Therefore, the correct answer is that the second reaction (Glycolate + O2 producing glyoxylate + hydrogen peroxide) is associated with photorespiration.

### Final Answer:
The chemical reactions associated with photorespiration are:
- Reaction 1: RuBP + O2 → PGA + phosphoglycolate (part of photorespiration)
- Reaction 2: Glycolate + O2 → glyoxylate + hydrogen peroxide (part of photorespiration)