Question

the proton gradient that drives atp synthesis during photosynthesis is generated by which of the following? an electron carrier that pumps protons out of the stroma into the thylakoid lumen an electron carrier that pumps protons out of the thylakoid lumen into the stroma an electron carrier that removes electrons from water the operation of two photosystems that work in series an electron carrier that receives electrons from photosystem i

Answer 1

The proton gradient for ATP synthesis during photosynthesis is generated by the action of the electron transport chain in pumping protons into the thylakoid lumen, which is initiated by photosystem II and contributes to the formation of an electrochemical gradient exploited by ATP synthase to produce ATP.

Step-by-step explanation:

The proton gradient that drives ATP synthesis during photosynthesis is generated by the electron transport chain that moves protons across the thylakoid membrane into the lumen. This process begins in photosystem II (PSII), where energy from sunlight is used to extract electrons from water. These electrons then travel down the electron transport chain to photosystem I (PSI), pumping protons into the thylakoid lumen and establishing an electrochemical gradient. The splitting of water also contributes to the proton buildup in the lumen. In contrast, the reduction of NADP+ to NADPH removes protons from the stroma, further enhancing the gradient. Finally, ATP synthase utilizes this gradient by allowing protons to flow back into the stroma, harnessing energy to synthesize ATP through a process called chemiosmosis.