Organic chemistry

Photosystem

Chlorophyll fluorescence

Biology

Biophysics

Photosynthesis

Chemistry

Chlorophyll

Chlorophyll a

Fucoxanthin

Carotenoid

Diatom

Chlorophyll c

Botany

Pigment

Photochemistry

Photosystem II

Science

All the hues, even the blues Photosynthetic organisms must balance maximizing productive light absorption and protecting themselves from too much light, which causes damage. Both tasks require pigments—chlorophylls and carotenoids—which absorb light energy and either transfer it to photosystems or disperse it as heat. Wang et al. determined the structure of a fucoxanthin chlorophyll a/c–binding protein (FCP) from a diatom. The structure reveals the arrangement of the specialized photosynthetic pigments in this light-harvesting protein. Fucoxanthin and chlorophyll c absorb the blue-green light that penetrates to deeper water and is not absorbed well by chlorophylls a or b. FCPs are related to the light-harvesting complexes of plants but have more binding sites for carotenoids and fewer for chlorophylls, which may help transfer and disperse light energy. Science , this issue p. eaav0365

Structural basis for blue-green light harvesting and energy dissipation in diatoms