chemiosmosis
/ˌkɛmɪɒzˈməʊsɪs/(also chemosmosis)
noun
Biochemistry. The diffusion of ions through a semipermeable membrane into a region of lower ion concentration (i.e. down an electrochemical gradient); especially that of hydrogen ions (protons) which forms part of the biochemical system for the synthesis of ATP and hence the transfer of energy in living organisms.
Origin
Late 19th century (in an earlier sense). Originally from chemo- + osmosis, after German Chemosmose. In later use perhaps partly after chemi-; compare e.g. chemiluminescence and also chemio-, variant of chemo-.