Final answer:
When photons strike photosystem II, pigments pass the light energy to chlorophyll molecules, exciting electrons. These electrons are then transferred to the electron transport chain, which eventually transfers them from pheophytin to photosystem I (PSI).
Step-by-step explanation:
When photons strike photosystem (PS) II, pigments pass the light energy to chlorophyll molecules that in turn excite electrons. These excited electrons are then passed to the electron transport chain.
The electron transport chain transfers the photoexcited electron from pheophytin, a pigment molecule in PSII, to photosystem I (PSI).
Overall, the flow of electrons from water through the Z-scheme in photosynthesis involves the transfer of photoexcited electrons from pheophytin to PSI.