Photorespiration is the light dependent process of oxygenation of RuBP (Ribulose Bisphosphate) and release of CO2,NH3 and finally O2. It occurs in chloroplast and mitochondria and peroxisomes are also required. HighO2 concentration, low CO2 and high temperature are required for this process to take place. In mitochondria two molecules of serine, with the simultaneous release of carbon dioxide and ammonia.