Dif.. photorespiration and normal respiration.
Photorespiration is a process in which oxidation of ribulose‐1,5‐bisphosphate takes place with the help of enzyme Rubisco, producing a 3‐carbon compound, 3‐phosphoglycerate, and a 2‐carbon compound, phosphoglycolate. It is considered as a wasteful process because about 25 % of the CO2 fixed during photosynthesis is lost during the process moreover there is no formation of ATP & NADH
The process of respiration involves inhalation and exhalation. During inhalation, the pressure in lungs is lower than the atmospheric pressure, so the air is drawn into the lungs from outside through nostrils. Similarly, when the pressure inside the lungs is more then the atmospheric pressure the air is released out , this is known as exhalation. The exchange of gases takes place at the alveolar surface.