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This pathway is known as cyclic photophosphorylation, and it produces neither O 2 nor NADPH. Unlike non-cyclic photophosphorylation, NADP + does not accept the electrons; they are instead sent back to the cytochrome b 6 f complex. [citation needed]
In cyclic photophosphorylation, cytochrome b 6 f uses electrons and energy from PSI to create more ATP and to stop the production of NADPH. Cyclic phosphorylation is important to create ATP and maintain NADPH in the right proportion for the light-independent reactions. The net-reaction of all light-dependent reactions in oxygenic photosynthesis ...
If electrons only pass through once, the process is termed noncyclic photophosphorylation, but if they pass through PSI and the proton pump multiple times it is called cyclic photophosphorylation. When the electron reaches photosystem I, it fills the electron deficit of light-excited reaction-center chlorophyll P700 + of PSI.
Ferredoxin: NADP + reductase is the last enzyme in the transfer of electrons during photosynthesis from photosystem I to NADPH. [2] The NADPH is then used as a reducing equivalent in the reactions of the Calvin cycle. [2] Electron cycling from ferredoxin to NADPH only occurs in the light in part because FNR activity is inhibited in the dark. [11]
Noncyclic electron transport or non-cyclic photophosphorylation produces NADPH + H + and ATP. Cyclic electron transport or cyclic photophosphorylation produces only ATP. The noncyclic variety involves the participation of both photosystems, while the cyclic electron flow is dependent on only photosystem I. Photosystem I uses light energy to ...
Nicotinamide adenine dinucleotide phosphate, abbreviated NADP [1] [2] or, in older notation, TPN (triphosphopyridine nucleotide), is a cofactor used in anabolic reactions, such as the Calvin cycle and lipid and nucleic acid syntheses, which require NADPH as a reducing agent ('hydrogen source'). NADPH is the reduced form, whereas NADP + is the ...
The Calvin cycle uses the chemical energy of ATP and the reducing power of NADPH from the light-dependent reactions to produce sugars for the plant to use. These substrates are used in a series of reduction-oxidation ( redox ) reactions to produce sugars in a step-wise process; there is no direct reaction that converts several molecules of CO 2 ...
In non-cyclic photophosphorylation, ferredoxin is the last electron acceptor thus reducing the enzyme NADP + reductase. It accepts electrons produced from sunlight-excited chlorophyll and transfers them to the enzyme ferredoxin: NADP + oxidoreductase EC 1.18.1.2.