Explanation

Photorespiration is the light dependent process, in which utilisation of oxygen and release of carbon dioxide by the photosynthetic organs of a plant takes place. Normally, photosynthetic organs are reverse in the light, i.e., uptake carbon dioxide and release oxygen. This process is pronounced in $C_{3}$-plants and negligible in $C_{4}$-plants. At high temperature, RuBP carboxylase functions as oxygenase and instead of fixing carbon dioxide, oxidises ribulose 1, 5-biphosphate to produce phosphoglyceric acid and phosphoglycolate (starting substrate). On hydrolyzing, it forms glycolate and then glyoxylate, glycine and serine respectively.