Question

The oxygenation activity of RuBisCO enzyme in photorespiration leads to the formation of

• A. 1 molecule of 6-C compound
• B. 1 molecule of 4-C compound and 1 molecule of 2-C compound
• C. 2 molecules of 3-C compound
• D. 1 molecule of 3-C compound

Answer 1

The correct option is D 1 molecule of 3-C compound

Photorespiration is the light dependent process. RuBP carboxylase (RuBisCO) has an active site that can accommodate both oxygen and carbon dioxide. In C3 plants, RuBP carboxylase functions as oxygenase and instead of fixing carbon dioxide (C3 cycle), it oxidises ribulose-1,5-bisphosphate to produce a 3-carbon phosphoglycerate and a 2-carbon phosphoglycolate.
Hence, only one molecule of 3-C compound is produced due to photorespiration.