Electric charge separation or quantum conversion occurs at

In the grana of the chloroplast,the reaction $ADP + \Pi = ATP$ during the day shows:

Assertion: The stromal thylakoids are rich in both $PS\, I$ and $PS\, II.$
Reason: The stroma membranes are rich in $ATP$ synthetase.

Which of the following elements are required for the photolysis of water?

$2 H_{2} O \rightarrow 4 H^{+} + O_{2} + 4 e^{-}$
Based on the above equation,answer the following questions:
$(a)$ Where does this reaction take place in plants?
$(b)$ What is the significance of this reaction?

The first acceptor of electrons from an excited chlorophyll molecule of photosystem $II$ is