During photorespiration, the oxygen consuming reaction (s) occur in
(a) Grana of chloroplasts and peroxisomes
(b) Stroma of chloroplasts
(c) Stroma of chloroplasts and mitochondria
(d) Stroma of chloroplasts and peroxisomes

Options

A. Grana of chloroplasts and peroxisomes
B. Stroma of chloroplasts
C. Stroma of chloroplasts and mitochondria
D. Stroma of chloroplasts and peroxisomes

Answer

**Step-by-Step Solution:**

1. **Understanding Photorespiration**: Photorespiration is a process that occurs in plants when the enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) binds with oxygen instead of carbon dioxide. This process is often considered wasteful because it consumes ATP and NADPH, which are also used in photosynthesis.

2. **Identifying the Reaction Locations**: The question asks where the oxygen-consuming reactions of photorespiration occur. The key organelles involved in this process are the chloroplasts and peroxisomes.

3. **Chloroplasts**: The initial reaction of photorespiration occurs in the stroma of the chloroplasts. Here, ribulose-1,5-bisphosphate (RUBP) reacts with oxygen, leading to the formation of 2-phosphoglycolate and 3-phosphoglycerate.

4. **Peroxisomes**: After the initial reaction in the chloroplasts, the resulting glycolate is transported to the peroxisomes. In the peroxisomes, glycolate is further processed, and oxygen is consumed in this organelle as well.

5. **Conclusion**: Since the oxygen-consuming reactions occur in both the stroma of chloroplasts and the peroxisomes, the correct answer to the question is option (d) - Stroma of chloroplasts and peroxisomes.

**Final Answer**: (d) Stroma of chloroplasts and peroxisomes.

---