Question

The essential element needed for water splitting in photosynthesis leading to $O_2$ evolution is

• A. Mo
• B. Mn
• C. Mg
• D. K

Answer 1

Answer: (B)

When photosystem-II becomes excited, it splits a molecule of water to release oxygen, i.e., photolysis of water takes place. Ions like manganese, chloride and calcium play an important role in splitting of water. $H_{2}O\underset{C{a}^{+2},M{n}^{+2},C{l}^{-}}{\overset{\text{ Light Energy }+P_{680}(PS-II)}{\to }}2H^{+}+\frac{1}{2}{O}_2+2e^{-}\downarrow$ Passed to oxidised $P_{680}$