The Calvin cycle is employed to fix carbon in the mesophyll cell of C3 plants, and RuBisCO is present there.
RuBisCO is a key carbon fixation enzyme that catalyzes the carboxylation of RuBP to create two molecules of -PGA, which is the initial step of carbon fixation.
RuBisCO is significant in organic chemistry because it catalyzes a critical synthesis reaction that allows inorganic carbon to enter the biosphere.