Photorespiration shows formation of

Photorespiration is the light dependent process of oxygenation of ribulose biphosphate (RuBP) and release of carbon dioxide by the photosynthetic organs of a plant. Normally photosynthetic organs do the reverse in the light, i.e., uptake of $\mathrm{CO}_2$ and release of $\mathrm{O}_2$. At high temperature, RuBP carboxylase functions as oxygenase and instead of fixing carbon dioxide ( $\mathrm{C}_3$ cycle), oxidises ribulose 1,5 -biphosphate to produce a 3-carbon phosphoglyceric acid and a 2-carbon phosphoglycolate. Photorespiration does not produce energy or reducing power. Rather, it consumes energy. Further, it undoes the work of photosynthesis. There is $25 \%$ loss of fixed $\mathrm{CO}_2$. Therefore, photorespiration is a highly wasteful process. This happens only in case of $C_3$ plants. $C_4$ plants have overcome the problem of photorespiration.