Answer:
a. Photorespiration
Explanation:
Photorespiration is the metabolic process that results from Rubisco's lack of specificity (O 2 consumption and light-related CO 2 production)
Photorespiration occurs due to the double activity exerted by the enzyme ribulose-1,5-bisphosphate carboxylase / oxygenase (rubisco), which catalyzes two competing reactions: the addition of CO2 to ribulose-1,5-bisphosphate (RuBP), forming two molecules of 3-phosphoglycerate (PGA), which are used in the thermochemical step of photosynthesis and the addition of O2 to RuBP, producing a PGA and a phosphoglycolate molecule, characterizing photorespiration.
Thus, the rubisco, present in chloroplasts, besides exerting the carboxylase activity, which initiates the Calvin cycle, is equally capable of exerting oxygenase activity, having both RuBP as substrate in both cases.
