Light-harvesting complexes of green plants

The light-harvesting complex (or antenna complex) is an array of protein and chlorophyll molecules embedded in the thylakoid membrane of plants, which transfer light energy to one chlorophyll a molecule at the reaction center of a photosystem.

The antenna pigments are predominantly chlorophyll b, xanthophylls, and carotenoids. Chlorophyll a is known as the core pigment. Their absorption spectra are non-overlapping in order to broaden the range of light that can be absorbed in photosynthesis. The carotenoids have another role as an antioxidant to prevent photo-oxidative damage of chlorophyll molecules. Each antenna complex has between 250 and 400 pigment molecules and the energy they absorb is shuttled by resonance energy transfer to a specialized chlorophyll-protein complex known as the reaction center of each photosystem. The reaction center initiates a complex series of chemical reactions that capture energy in the form of chemical bonds.