NEETBotanyPhotosynthesis in Higher Plants
Why does photorespiration not occur in C4 plants?
Options
- AThey lack RuBisCO
- BThey have a mechanism that increases the concentration of CO2 at the enzyme site
- CThey do not perform photosynthesis
- DThey only use O2 for respiration
Correct answer
B. They have a mechanism that increases the concentration of CO2 at the enzyme site
Step-by-step solution
In C4 plants photorespiration does not occur. This is because they have a mechanism that increases the concentration of CO2 at the enzyme site. This takes place when the C4 acid from the mesophyll is broken down in the bundle sheath cells to release CO2 – this results in increasing the intracellular concentration of CO2 . In turn, this ensures that the RuBisCO functions as a carboxylase minimising the oxygenase activity. Now that you know that the C4 plants lack photorespiration, you probably can understand why pro