The primary electron acceptor during the ionization of water is:

Minerals involved in the photooxidation of water are:

What happens when the proton gradient breaks down?

Cyclic photophosphorylation results in the formation of

The following $(I-VI)$ are the main steps of chemiosmotic $ATP$ synthesis in the light reaction. Arrange them in the correct order:
$I$. $H^+$ concentration gradient established
$II$. $H^+$ diffuses through $ATP$ synthase
$III$. Carriers use energy from electrons to move $H^+$ across the membrane
$IV$. Electrons from $PS-II$ pass along the electron transport chain
$V$. Light excites electrons in $PS-II$
$VI$. Energy of $H^+$ flow is used by $ATP$ synthase to make $ATP$

By which of the following complexes is a proton pumped to reach $ATP$ synthase to participate in $ATP$ synthesis?