Give comparison between the following: (b) Cyclic and non-cyclic photophosphorylation
Explanation In cyclic photophosphorylation, only PSI is involved whereas in non-cyclic PSI and PSII both are involved. In cyclic photophosphorylation photolysis of water is absent whereas in noncyclic photolysis of water occurs. In cyclic photophosphorylation, oxygen formation does not occur whereas in non-cyclic oxygen is formed. In cyclic photophosphorylation, no NADPH synthesis occurs whereas non-cyclic NADPH synthesis occurs.Noncyclic is a light-induced electron transport from water to NADP⁺ and a concomitant evolution of oxygen. In certain cases, photoexcited electrons follow the cyclic path, which involves PSI but not PSII. The formation of ATP due to light-induced non-cyclic electron flow is called non-cyclic photophosphorylation. In cyclic electron flow, photoexcited electrons from P700 of PSI move through the b6f complex and back to P700.
