Differentiate, distinguish, compare and explain what is the main difference between cyclic and non-cyclic photophosphorylation.
Difference between Cyclic and Non-cyclic photophosphorylation
1. Cyclic photophosphorylation is performed by photosystem I independently. Non-cyclic photo phosphorylation is performed by collaboration of both photosys-tems I and II.
2. Cyclic is not connected with photolysis of water. Therefore, no oxygen is evolved. Non-cyclic is connected with photolysis of water and libera-tion of oxygen.
3. Cyclic synthesises only ATP. Non-cyclic photophosphorylation is not only connected with ATP synthesis but also production of NADPH.
4. Cyclic photophosphorylation operates under low light intensity, anaerobic conditions or when CO2 availability is poor. Non-cyclic photophosphorylation takes place under optimum light, aerobic conditions and in the pres-ence of carbon dioxide.
5. Cyclic occurs mostly in stromal or intergranal thylakoids. Non cyclic occurs in the graml thylakoids.
6. ATP synthesis is not affected by DCMU in cyclic. DCMU inhibits non-cyclic photophosphorylation.