(N/A) The electrons that were removed from photosystem-$II$ $(PS-II)$ must be replaced to maintain the continuous flow of electrons.
This is achieved by electrons made available through the splitting of water,a process known as photolysis.
Explanation of the process:
- The splitting of water is associated with $PS-II$. Water is split into protons $(H^+)$,nascent oxygen $([O])$,and electrons $(e^-)$.
- The chemical equation for this process is: $2H_2O \longrightarrow 4H^+ + O_2 + 4e^-$.
- This reaction releases oxygen $(O_2)$ as a byproduct,which is one of the net products of photosynthesis.
- The electrons required to replace those removed from $PS-II$ are provided by this water-splitting complex.
- The water-splitting complex is physically located on the inner side of the thylakoid membrane,ensuring that the protons released accumulate within the lumen.