photosystem

noun pho·to·sys·tem \ˈfō-tō-ˌsis-təm\

Definition of PHOTOSYSTEM

: 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

1964

Next Word in the Dictionary: phototacticPrevious Word in the Dictionary: photosynthetic ratioAll Words Near: photosystem

What made you want to look up photosystem? Please tell us where you read or heard it (including the quote, if possible).

Put-downs with flair

How to use a word that (literally) drives some people nuts.

Test your vocab with our fun, fast game

Ailurophobia, and 9 other unusual fears