Grasses have anadaptive mechanism to compensate photorespiratory lossesName and describe the mechanism.

Explanation

Rate of respiration is more in light than in dark. Photorespiration is the excess respiration taking place in photosynthetic cells due to absence of `CO_2` and increase of `O_2`. This condition changes the carboxylase role of RUBISCO into oxygese. `O_2` Cycle takes place in chloroplast, peroxisome and mitochondria. RUBP is converted into PGA and a 2C-compound phosphoglycolate by Rubisco enzyme in chloroplast. Since the first product is a 2C-compound, this cycle is known as `O_2` Cycle. Phosphoglycolate by loss of phosphate becomes glycolate. Glycolate formed in chloroplast enters into glycine and transferred into mitochondria. In mitochondria, two molecules of glycine combine to form serine. Serine enters into peroxisome to form hydroxy pyruvate. Hydroxy pyruvate with help of DH + `H^+` becomes glyceric acid. Glyceric acid is cycled back to chloroplast utilizing ATP and becomes Phosphoglyceric and (PGA) and enters into the Calvin cycle (PCR cycle). Photorespiration does not yield any free energy in the form of ATP. Under certain conditions 50% of the photosynthetic potential is lost because of Photorespiration.