The Consequences Of Cyclic And Noncyclic Electron Flows

There are two different ways that electron flows, cyclic and noncyclic (linear). Noncyclic Electron flow is important for processes such as the synthesis of ATP and NADPH, since it is the key to the energy transformation in these mechanisms (Campbell 195). Linear/Noncyclic electron flow occurs mainly during light reactions of photosynthesis by having the flow of electrons go through the photosystems and other molecular components that are built into the thylakoid membrane (Campbell 195). They generate NADPH and oxygen during in its processes and utilizes both Photosystem I and II (Campbell 196). On the other hand, Cyclic electron flow occurs when photoexcited electrons take an alternative path (Campbell 196). This uses the photosystem I but not the photosystem II (Campbell 196). Cyclic flow can also be seen as a short circuit, with the electrons cycling back from the ferredoxin (Fd) to the cytochrome complex and onto other components (Campbell 196). Unlike linear electron flow, cyclic electron flow is used to create different products, for example, cyclic electron flow is not involved in the production of NADPH and does not release oxygen during its processes--however, it does generates ATP (Campbell 196). The ATP is generated by the protons moving …show more content…
In both cyclic and noncyclic electron flows, the molecule chlorophyll a, which is at the center of photosystem I (called P700), is used in both cyclic and noncyclic electron flows (Campbell 194). It is called P700 because the most effective wavelength of light it absorbs is 700 nm: the far end part of the red light spectrum (Campbell 195). However, unlike cyclic electron flows which uses only P700, noncyclic electron flow also uses P680. P680 absorbs light at 680 nm and linear flow electrons utilizes it for its electron donating component and is present in Photosystem II (Campbell 196). Since P700, light at wavelength 700 nm, is present in both cyclic and noncyclic processes, this statement is