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The oxygenase activity of the ribulose-1,5-bisphosphate-carboxylase/oxygenase (RUBISCO) enzyme initiates photorespiration. Because RUBISCO works on oxygen rather than the carbon dioxide required for photosynthetic reaction initiation, it is regarded as a wasteful route. Photorespiration is rarely reduced in C₃ plants due to a lack of a specific system.

• C₄ plants reduce photorespiration by splitting the CO₂ fixation and Calvin cycle activities and performing them in various cell types.

• CO₂ is taken up by Phosphoenolpyruvate (PEP) in mesophyll cells and converted to oxaloacetate.

• Malate is made from oxaloacetate, which enters Kreb's cycle and invests in the bundle-sheath cells. It then returns as a PEP to Mesophyll cells, where the cycle begins again.

• Crassulacean Acid Metabolism (CAM) plants perform the same process at different times of the day and night, conserving water and reducing photorespiration.

Therefore, plants try to avoid photorespiration in the above-given ways.