C3 plants :-
० Found in all photosynthetic plants.
० Plants that use the cycle can be hydrophytic, mesophytic and xerophytic.
० Photoactive Stomata.
० High rate of Photorespiration.
० Normal Leaf anatomy.
० For the synthesis of glucose molecule or 6CO2 fixation : 12 NADPH and 18 ATPs are required.
० Single CO2 fixation occurs.
० Primary CO2 atmospheric acceptor RUBP.
० First stable product 3PGA.
० First enzyme involved RUBISCO.
० Carbon dioxide compensation point: 30-70PPM.
C4 Plants :-
० Only in tropical plants.
० Plants that use the cycle can be mesophytic.
० Photoactive Stomata.
० Photorespiration: less or negligible.
० Kranz anatomy.
० 12 NADPH and 30 ATPs are required.
० Double carbon dioxide fixation.
० Atmosphere Co2 acceptor- PEP(In mesophyll cell) and Metabloic Co2 acceptor-RUBP(In bundle sheath cell).
० First stable product OAA (Oxalo acetic acid).
० First enzyme involved PEP Carboxylase.
० CO2 compensation point: 10PPM.