Light-driven uptake of oxygen and release of carbon dioxide, the carbon being derived from the early reactions of photosynthesis.
A process that begins when rubisco fixes molecular oxygen, as opposed to carbon dioxide, which ultimately leads to the evolution of CO2 from plants. This process of carbon loss is stimulated by conditions of high light, temperature and oxygen concentration.
fo-to-res-per-A-shun A process that counters photosynthesis. 160
Photorespiration refers to the alternate pathway for production of Glyceraldehyde 3-phosphate by Rubisco, the main enzyme of the Dark reactions of photosynthesis (also known as the Calvin cycle or the Primary Carbon Reduction (PCR) cycle). Although Rubisco favors carbon dioxide to oxygen,(approximately 3 carboxylations per oxygenation), oxygenation of Rubisco occurs frequently, producing a glycolate and a glycerate. This usually occurs when oxygen levels are high; for example, when the stomata (tiny pores on the leaf) are closed to prevent water loss on dry days.