Biology

RuBisCO is essential for the initial step of the Calvin cycle (carbon fixation), and its inhibition will prevent the cycle from proceeding.

The primary function of RuBisCO in the Calvin cycle (light-independent reactions) is to catalyze the reaction between carbon dioxide (CO₂) and ribulose bisphosphate (C₅) to form two molecules of 3-phosphoglycerate (C₃). This is the initial step of carbon fixation, where inorganic carbon from CO₂ is incorporated into an organic molecule, like glucose.

If a plant is exposed to a chemical that inhibits RuBisCO, the enzyme cannot perform its function of fixing carbon dioxide. Without the ability to fix carbon dioxide, the subsequent steps of the Calvin cycle, which rely on the products of the initial carbon fixa...