Answer the following question given this paragraph: 

Figure 8.15 A photosystem consists of a light-harvesting complex and a reaction center. Pigments in the lightharvesting complex pass light energy to two special chlorophyll a molecules in the reaction center. The light excites an electron from the chlorophyll a pair, which passes to the primary electron acceptor. The excited electron must then be replaced. In (a) photosystem II, the electron comes from the splitting of water, which releases oxygen as a waste product. In (b) photosystem I, the electron comes from the chloroplast electron transport chain discussed below.


Q: In a photosystem, pigments in the light-harvesting complex pass light energy to two special molecules of what in the reaction center?


A:
chlorophyll