PLANT PHYSIOLOGY
PHOTOSYNTHESIS
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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H+ and excited electrons
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Excited electrons and ATP
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Hydrogen ions and glucose
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Excited electrons and proteins
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Detailed explanation-1: -The electron is attached to a primary electron acceptor (different from the one associated with Photosystem II). The electron is passed again through a series of redox reactions, eventually joining NADP+ and H+ to form NADPH. Electrons flow continuously from water to NADPH.
Detailed explanation-2: -The reduced state of NADP is NADPH. Energy from sunlight is used to extract electrons from water once a photon strikes the photosystem II (PSII) reaction center. The electrons move to photosystem I (PSI), which converts NADP+ to NADPH, via the chloroplast electron transport chain.
Detailed explanation-3: -Generating Another Energy Carrier: NADPH As the electron from the electron transport chain arrives at photosystem I, it is re-energized with another photon captured by chlorophyll. The energy from this electron drives the formation of NADPH from NADP+ and a hydrogen ion (H+).
Detailed explanation-4: -NADPH is formed on the stromal side of the thylakoid membrane, so it is released into the stroma. In a process called non-cyclic photophosphorylation (the “standard” form of the light-dependent reactions), electrons are removed from water and passed through PSII and PSI before ending up in NADPH.
Detailed explanation-5: -The final electron acceptor is NADP+, which is reduced to NADPH. NADPH generated from light reactions is used in sugar synthesis in dark reactions. Light reactions also generate a proton motive force across the thylakoid membrane, and the proton gradient is used to synthesize ATP.