Final answer:
In cyclic phosphorylation, electrons are transferred to plastocyanin (PC) and used to generate ATP as they cycle back to Photosystem I.
Step-by-step explanation:
In cyclic phosphorylation, electrons are transferred to plastocyanin (PC) to make ATP. When the reaction center pigment in Photosystem I (PSI) is excited by light, it transfers an excited electron to the electron transport chain (ETC).
As the electron moves down the ETC, a proton gradient is established across the membrane, which is critical for ATP synthesis.
The flow of protons back through ATP synthase enables the enzymatic addition of phosphate groups to ADP, thereby generating ATP. Unlike non-cyclic phosphorylation, the electrons return to PSI rather than being donated to NADP+ in the ETC.
Thus, in cyclic phosphorylation, the same electrons are used over and over to produce ATP.
In cyclic phosphorylation, electrons are transferred to the PSI electron acceptor to make ATP.
During cyclic phosphorylation, the electrons excited from P700 in photosystem I (PSI) are transferred back to the PSI electron acceptor instead of being used to reduce NADP+ and generate NADPH. This results in the production of ATP through ATP synthase.
The electrons flow in a cyclic manner, going from PSI to the electron transport chain and back to PSI, hence the name cyclic phosphorylation.