Class 11 NEET Biology Photosynthesis in Higher Plants

(a) : The primary acceptor of CO2, is a 3 carbon compound phosphoenol pyruvic acid. Addition of CO2 to any compound is called carboxylation. In C4 cycle, CO2 combines with phosphoenol pyruvic acid to form oxaloacetic acid, with the help of enzyme phosphoenol pyruvate carboxylase (PEPCo). The oxaloacetic acid breaks up into pyruvic acid and CO2 which combines with RuBP to form PGA as in Calvin cycle.