Q. The first electron acceptor in photosystem- I of the cyclic photophosphorylation is :

Q. The first electron acceptor in photosystem- I of the cyclic photophosphorylation is :

(a) Ferredoxin.

(b) Cytochrome.

(c) Plastocyanin.

(d) Plastoquinone.

Solution :

Correct option : A During cyclic photophosphorylation, photosystem II is not involved. Only photosystem I is involved and ATP is synthesized alone. Reduced coenzyme NADPH₂ are not produced. The electron acceptor in photosystem I is ferredoxin. In non cyclic electron flow, it passes on electrons to oxidised NADP but in cyclic electron flow it passes on electrons to cytochrome b₆-f complex present in thylakoid membrane.