[Campbell Biology P.11] In the linear electron flow of the light reactions, what is the dir... | Practice Question

In the linear electron flow of the light reactions, what is the direct source of electrons that replenish Photosystem II's reaction center chlorophyll P680 after it loses electrons to the primary electron acceptor?

  • A: Electrons from Photosystem I
  • B: Electrons released from glucose
  • C: Electrons from the splitting of water molecules
  • D: Electrons from the cytochrome complex

Explanation

The reaction center chlorophyll of Photosystem II P680 becomes oxidized after donating electrons to the primary electron acceptor. These lost electrons are directly replenished by the splitting of water molecules photolysis , which also releases protons and molecular oxygen O2 as a byproduct.