photosystem

noun

pho·​to·​sys·​tem ˈfō-tō-ˌsi-stəm 

: either of two photochemical reaction centers consisting chiefly of photosynthetic pigments complexed with protein and occurring in chloroplasts:

a

: one that absorbs light with a wavelength of about 700 nanometers

called also photosystem I

b

: one that absorbs light with a wavelength of about 680 nanometers

called also photosystem II

Example Sentences

Recent Examples on the Web

Instead, for a safe, steady energy output, the pigments of the photosystem had to be very finely tuned in a certain way. —Quanta Magazine, 30 July 2020

Word History

First Known Use

1961, in the meaning defined above