Question
Best defined function of manganese in green plants is
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Photolysis of water
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Calvin cycle
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Nitrogen fixation
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Water absorption
Solution
A.
Photolysis of water
Photolysis of water requires light energy, an Oxygen-Evolving Complex (OEC) and electron carrier 1/2. OEC complex was formerly called Z-enzyme. It has four Mn ions. Light energy brings about changes in Mn (Mn+2, Mn3+, Mn+4) which helps in removing electrons from OH- component of water forming oxygen. Liberation of oxygen also requires Cl- and Ca+2.
