Question

During phenomenon of photorespiration the oxygen consuming steps occurs at

• A. Chloroplast and mitochondria
• B. Mitochondria and peroxisome
• C. Peroxisome and chloroplast
• D. Only chloroplast

Answer 1

Answer: (C)

Peroxisome and chloroplast

The initial oxygenation reaction by RuBiSCO occurs in the chloroplast. This is where O${}_2$ is consumed by photorespiration. The 2-phosphoglycolate that is formed is dephosphorylated and exported as glycolate to the peroxisome. The glycolate is then converted to glyoxylate. This reaction consumes O${}_2$ and generates hydrogen peroxide.

So, the correct option is 'Peroxisome and chloroplast'.