medical Definition of proton pump
: a molecular mechanism that transports hydrogen ions across cell membranes
- The physiological essence of the proton pump is to exchange extracellular K+ for intracellular H+.
- —John E. Hoover, Remington: The Science and Practice of Pharmacy, 21st edition, 2005
- Chemical gradients have been used to create asymmetry in the environment, as in the case of proton pumps to couple chemical energy with molecular motion.
- —Jay Siegel, Science, 7 Oct. 2005
