Ferredoxin is a component of

Photophosphorylation occurs in

Assertion $(A) : H^+$ gradient across the thylakoid membrane is essential for the formation of $\text{ATP}$.
Reason $(R) :$ Breakdown of $H^+$ gradient due to the movement of protons through $F_0$ of $\text{ATP}$ synthase releases enough energy to activate $\text{ATP}$ synthase enzyme that catalyses the formation of $\text{ATP}$.

Select the correct option for cyclic photophosphorylation.

Photophosphorylation is the synthesis of ..........

Which of the following is the primary electron acceptor from the chlorophyll molecule of Photosystem-$II$?