Question

A green plant starts evolving carbon dioxide instead of oxygen on a hot summer day. Explain.

Answer 1

On a hot sunny day, the enzyme RuBisCo carries out the oxygenation of RuBP instead of carboxylation. The process of Photorespiration takes place and a compound is 2-PGA is formed and then later converted into 3-phosphoglyceric acid with the release of oxygen. The key enzyme that accomplishes the fixing of carbon is Rubisco, and at low concentrations of CO₂ it begins to fix oxygen instead. Under moderate temperature conditions when C3 plants have sufficient water, the supply of carbon dioxide is abundant and photorespiration is not a problem.