Final answer:
A photosystem consists of the reaction-center complex, the primary electron acceptor, the chlorophyll molecules, and the light-harvesting complexes.
Step-by-step explanation:
A photosystem consists of several structures: the reaction-center complex, the primary electron acceptor, the chlorophyll molecules, and the light-harvesting complexes. The reaction-center complex contains special chlorophyll a molecules that can undergo oxidation upon excitation, converting light energy into an excited electron. The primary electron acceptor accepts this excited electron. The chlorophyll molecules and the light-harvesting complexes capture and pass light energy to the reaction center.