Photosynthesis - antenna proteins - Gloeocapsa sp. PCC 7428

The chlorophyll-binding subunits of photosystems I and II are internal antenna light-harvesting proteins of oxygenic photosynthesis. The antenna proteins that exist in phycobilisomes in cyanobacteria and light-harvesting chlorophyll protein complexes in green plants act as peripheral antenna systems, enabling more efficient absorption of light energy.