NEET2018BotanyPhotosynthesis in Higher PlantsActual
Assertion : Cyclic photophosphorylation synthesises ATP. Reason : ATP synthesis in cyclic photophosphorylation is associated with NADPH formation.
Options
- AIf both assertion and reason are true and reason is the correct explanation of assertion.
- BIf both assertion and reason are true but reason is not the correct explanation of assertion.
- CIf assertion is true but reason is false.
- DIf both assertion and reason are false.
Correct answer
C. If assertion is true but reason is false.
Step-by-step solution
In case of cyclic photophosphorylation, the electron while passing between ferredoxin and plastoquinone and/or over the cytochrome complex, loses sufficient energy to form ATP from ADP and inorganic phosphate. In cyclic photophosphorylation no NADPH formation takes place. But in case of noncyclic photophosphorylation, NADP - reduced through H ⁺ released during photolysis forms NADPH. ATP synthesis is not direct and the energy released by electron is actually used for pumping H ⁺ ions across the thylakoid membrane.