PLANT PHYSIOLOGY
PHOTOSYNTHESIS
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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It reduces H2O into H+ and O
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O2 is actually generated in the Calvin Cycle
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It Oxidizes H2O into H+ and O
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Oxygen atoms are assembled in Photosystem II
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Detailed explanation-1: -Photosystem II (PSII) uses light energy to split water into protons, electrons and O2.
Detailed explanation-2: -The oxygen-evolving center of photosystem II is a complicated cluster of manganese ions (magenta), calcium (blue green) and oxygen atoms (red). It grips two water molecules and removes four electrons, forming oxygen gas and four hydrogen ions.
Detailed explanation-3: -Photosystem II obtains replacement electrons from water molecules, resulting in their split into hydrogen ions (H+) and oxygen atoms. The oxygen atoms combine to form molecular oxygen (O2), which is released into the atmosphere. The hydrogen ions are released into the lumen.
Detailed explanation-4: -The water oxidation to evolve dioxygen is catalyzed at the oxygen-evolving center (OEC) in photosystem II (PS II) in photosynthesis.
Detailed explanation-5: -The two electrons lost from photosystem II are replaced by the splitting of water molecules. Water splitting also releases hydrogen ions into the lumen. This contributes to a hydrogen ion gradient similar to the one created by mitochondrial electron transport.