Doubt by ashish

In NCRET is written photorespiration"rather it results in release of carbon dioxide with the uutlisation of atp. so in which step of photosynthesis ATP is used and how much?

 

Answers

Answer by Isha Agarwal

Photorespiration (also known as the oxidative photosynthetic carbon cycle, or C2 photosynthesis) refers to a process in plant metabolism where the enzyme RuBisCO oxygenates RuBP, wasting some of the energy produced by photosynthesis. PGA is the normal product of carboxylation, and productively enters the Calvin cycle. Phosphoglycolate, however, inhibits certain enzymes involved in photosynthetic carbon fixation.In higher plants it is salvaged by a series of reactions in the peroxisome, mitochondria, and again in the peroxisome where it is converted into glycerate. Glycerate reenters the chloroplast and by the same transporter that exports glycolate. A cost of 1 ATP is associated with conversion to 3-phosphoglycerate (PGA) (Phosphorylation), within the chloroplast, which is then free to re-enter the Calvin cycle. Instead of producing ATP, photorespiration uses ATP.