<unk>  is the diffusion of ions across a selectively-permeable membrane. More specifically, it relates to the generation of ATP by the movement of hydrogen ions across a membrane during cellular respiration.
Hydrogen ions (protons) will diffuse from an area of high proton concentration to an area of lower proton concentration. Peter Mitchell proposed that an electrochemical concentration gradient of protons across a membrane could be harnessed to make ATP. He likened this process to osmosis, the diffusion of water across a membrane, which is why it is called<unk> .
ATP synthase is the enzyme that makes ATP by<unk> . It allows protons to pass through the membrane using the kinetic energy to phosphorylate ADP making ATP. The generation of ATP by<unk>  occurs in chloroplasts and mitochondria as well as in some bacteria.
Chemiosmosis
Osmotic diuresis
Rebound diuresis
Hemoconcentration
Vapor-liquid equilibrium
Enuresis
Third spacing of fluids
Kaliuresis