Question

Rubisco:

• A. catalyzes the carboxylation of CO2 to ribulose 1,5-bisphosphate
• B. initiates photorespiration when the CO2/O2 ratio is low.
• C. catalyzes the reduction of two molecules of PGAL to form glucose.
• D. a and b but not c

Answer 1

The correct option is D

a and b but not c

Rubisco catalyzes the carbon fixation of ribulose 1,5-bisphosphate, which initiates the Calvin cycle. At low concentrations of CO${}_2$ it initiates photorespiration.