PHOTOSYNTHESIS
LIGHT DEPENDENT REACTIONS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Oxygen ions are released into the thylakoid space.
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Water molecules are created.
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Electrons are released into the electron transport system.
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Hydrogen is released as waste.
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Detailed explanation-1: -The light excites an electron from the chlorophyll a pair, which passes to the primary electron acceptor. The excited electron must then be replaced. In (a) photosystem II, the electron comes from the splitting of water, which releases oxygen as a waste product.
Detailed explanation-2: -A photon strikes the antenna pigments of photosystem II to initiate photosynthesis. The energy travels to the reaction center that contains chlorophyll a to the electron transport chain, which pumps hydrogen ions into the thylakoid interior. This action builds up a high concentration of ions.
Detailed explanation-3: -Light energy causes the excitation and loss of an electron from a PSII reaction center chlorophyll (P680). Water is oxidized to replace the lost electron, generating H+ ions and oxygen (O-2) ions. These O-2 ions combine to form the diatomic O2. The excited electron is boosted to a higher energy state.
Detailed explanation-4: -After light excites the electron and they leave Photosystem II to travel down the first electron transport chain, how are these electrons replaced to Photosystem II? Oxygen is reduced and the electrons are given to the chlorophyll molecules of photosystem II.