In both cyclic and non-cyclic phosphorylation, light energy is absorbed by chlorophyll in the photosystem and is used to excite electrons. However, there are some differences between the two processes.
1. Cyclic phosphorylation: This type of phosphorylation occurs only in photosystem I. The excited electrons are passed through an electron transport chain, which generates ATP through chemiosmosis. The electrons are then returned to chlorophyll in photosystem I, creating a cyclic electron flow. Only ATP is produced during cyclic phosphorylation, and no reducing agents such as NADPH are generated.
2. Non-cyclic phosphorylation: This type of phosphorylation involves both photosystems I and II. Excited electrons are passed from photosystem II to photosystem I through an electron transport chain. This generates both ATP and NADPH. In addition, photosystem II also splits water molecules to release oxygen gas as a byproduct. The overall process of non-cyclic phosphorylation provides both energy (ATP) and reducing power (NADPH) for the light-independent reactions of photosynthesis.
Overall, cyclic phosphorylation is a simpler process that generates only ATP, while non-cyclic phosphorylation is a more complex process that produces both ATP and reducing agents like NADPH.
In both cyclic and non cyclic phosphorylation?
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