What determines whether rubisco acts as an oxygenase or a carboxylase? A) Rubisco has ten times more affinity for O₂ than for CO₂; therefore, it favors O₂ fixation. B) If O₂ is relatively abundant, rubisco acts as a carboxylase. C) If O₂ predominates, rubisco fixes it, and the Calvin cycle occurs. D) Oxygenase activity is more likely at low temperatures. E) As the ratio of CO₂ to O₂ falls in the leaf, the reaction of rubisco with O₂ is favored.

Question

Quizplus · Accepted Answer

Rubisco acts as an oxygenase when the ratio of CO₂ to O₂ is low, leading to photorespiration.

What Determines Whether Rubisco Acts as an Oxygenase or a Carboxylase