pigment-valk kompleksid, mis koosnevad valgust absorbeerivast antennist ja valgusenergiat redoksreaktsioonide keemiliseks energiaks muundavast fotokeemilise reaktsiooni tsentrist, Pigment-protein complexes consisting of a light-absorbing antenna and a photochemical reaction centre, which turns the light energy into chemical energy through redox-reaections. Higher plants and cyanobacteria have co-operating photosystems I and II.