Differences between Cyclic and Non-cyclic Photophosphorylation
Cyclic Photophosphorylation
Synthesis: It synthesizes only ATP.
Oxygen: Oxygen is not evolved.
Requirement: It requires only PS-I.
Cycling: Electron emitted by P700 is recycled back and no external source of electron is needed.
Performance: This process is operative at low light intensity, less availability of CO2 and under anaerobic conditions.
Operation: It does not usually operate for photosynthesis except bacteria.
Non-cyclic Photophosphorylation
Synthesis: It forms ATP as well as NADPH2.
Oxygen: Oxygen is liberated due to photolysis of water.
Requirement: It is performed with collaboration of PS-I and PS-II.
Cycling: It needs external electron donor.
Performance: It performs best under optimum light, presence of CO2 and under aerobic conditions.
Operation: It is functional for normal CO2 fixation.