Name the two important enzymes of C3 and C4 pathway, respectively What important role do they play in fixing CO2 ?

 

 
The important enzyme of C3 cycle is RuBP carboxylase oxygenase which catalyses PGA reaction of carboxylation of ribulose bis-phosphate, which is 5-carbon compound to form the first stable product in C3 cycle.

In C4 cycle, the important enzyme is phosphoenol pyruvate carboxylase (PEP carboxylase) which help in fixing CO2 to form oxaloecetate (4-carbon compound), the firsi stable product of dark reaction is C4 cycle.