Final answer:
In photosynthesis, the excited electrons move from Photosystem II (PSII) to Photosystem I (PSI) through the electron transport chain. The cytochrome complex transfers the electrons and protons across the thylakoid membrane, while the light-dependent reaction produces ATP and NADPH to power the Calvin cycle.
Step-by-step explanation:
Photosystem I (PSI) and Photosystem II (PSII) are two major components of the photosynthetic electron transport chain. When photons strike PSII, pigments pass the light energy to chlorophyll molecules, exciting the electrons. These excited electrons are then passed to the electron transport chain, which includes a cytochrome complex. The cytochrome complex transfers the electrons from PSII to PSI, while also transferring protons across the thylakoid membrane. The products of the light dependent reaction, including ATP and NADPH, are then used to power the Calvin cycle, which produces glucose.