Reduction of NADP in cyclic photophosphorylation

In summary, the process of photosystem 1 involves an electron jumping to an excited state after absorbing a photon, then moving through electron acceptors before returning to photosystem 1. NADP gets reduced using the energy the electron lost while moving between acceptors, even though the electron eventually returns to photosystem 1. This is because the electron is not incorporated into NADP, but rather helps to set up the proton gradient for the production of ATP. Cyclic photophosphorylation does not produce NADPH + H+, so it is unclear how photoautotrophs that only use this process perform the Calvin cycle and produce carbohydrates. The purpose of cyclic photophosphorylation was to support non-cyclic phot
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I understand that an electron jumps to an excited state after absorbing a photon with the right energy (frequency) in photosystem 1 and exits the structure of the primary pigment, moves through different electron acceptors and returns to photosystem 1 (now at a lower energy state). What I don't understand is why NADP gets reduced using the energy the electron lost while moving between electron acceptors. Gain of electrons corresponds to reduction, but surely the electron returns back to the photosystem, and is not incorporated into NADP? How can reduced NADPH be formed if there is no hydrogen gain either (since photolysis does not occur in cyclic photophosphorylation)? If NADPH is not formed, then how do photoautotrophs that only use cyclic photophosphorylation perform the Calvin cycle (and produce a carbohydrate)?
 
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true NADPH +H+ is not formed in cyclic photophosphorylation but..
i'm a bit unaware as to which plant performs ONLY cyclic photophosphorylation ...could you please tell me that...because the whole reason for evolution to bring in cyclic phosphorylation was to support non-cyclic with setting up the proton gradient (PMF)
 

What is cyclic photophosphorylation?

Cyclic photophosphorylation is a process in photosynthesis where light energy is used to produce ATP (adenosine triphosphate) through the transfer of electrons in a cyclic pathway. This process occurs in the thylakoid membrane of chloroplasts.

What is the role of NADP in cyclic photophosphorylation?

NADP (nicotinamide adenine dinucleotide phosphate) is a coenzyme that acts as an electron carrier in photosynthesis. It is reduced to NADPH during the light-dependent reactions of photosynthesis, and this reduced form is then used as a source of electrons in the Calvin cycle to produce organic compounds.

How is NADP reduced in cyclic photophosphorylation?

In cyclic photophosphorylation, NADP is reduced through the transfer of high-energy electrons from photosystem I to the NADP molecule. This process is facilitated by the enzyme NADP reductase, which uses the energy from light to drive the reduction reaction.

What is the difference between cyclic and non-cyclic photophosphorylation?

The main difference between cyclic and non-cyclic photophosphorylation is the pathway of electron flow. In cyclic photophosphorylation, the electrons circulate back to the original photosystem and are not used to reduce NADP, while in non-cyclic photophosphorylation, the electrons are transferred to NADP to produce NADPH. Additionally, cyclic photophosphorylation only produces ATP, while non-cyclic produces both ATP and NADPH.

What is the importance of cyclic photophosphorylation in photosynthesis?

Cyclic photophosphorylation plays a crucial role in maintaining the balance of energy and reducing power in photosynthesis. It helps to produce ATP, which is used as an energy source for cellular processes, and also helps to generate a pool of NADPH, which is necessary for the synthesis of organic compounds in the Calvin cycle. Additionally, cyclic photophosphorylation can also help protect the plant from damage by dissipating excess energy in the form of heat.

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