Q287
Photorespiration in C3 plants starts from
A.
Phosphoglycerate
B.
Phosphoglycolate
AnswerC.
Glycerate
D.
Glycine
Answer: Option B
Solution
Answer: Option B
Solution:
Photorespiration in C3 plants starts from Phosphoglycolate.Photorespiration refers to a process in plant metabolism where the enzyme RuBisCO oxygenates RuBP, wasting some of the energy produced by photosynthesis. The oxygenation reaction of RuBisCO is a wasteful process because 3-phosphoglycerate is created at a lower rate and higher metabolic cost compared with RuBP carboxylase activity.
PGA is the normal product of carboxylation and productively enters the Calvin cycle. Phosphoglycolate, however, inhibits certain enzymes involved in photosynthetic carbon fixation.