proton pump(redirected from Proton channel)
1. an apparatus for drawing or forcing liquid or gas.
2. to draw or force liquids or gases.
blood pump a machine used to propel blood through the tubing of extracorporeal circulation devices.
breast pump a pump for taking milk from the breast.
calcium pump the mechanism of active transport of calcium (Ca2+) across a membrane, as of the sarcoplasmic reticulum of muscle cells, against a concentration gradient; the mechanism is driven by hydrolysis of ATP.
enteral feeding pump an infusion pump specifically designed for administration of a solution through a feeding tube.
insulin pump see insulin pump.
intra-aortic balloon pump see intra-aortic balloon pump.
muscle pump compression of veins by the contraction of skeletal muscles, forcing blood towards the heart against the flow of gravity; seen particularly in the deep veins of the lower limbs. Called also venous pump.
Na+-K+ pump sodium-potassium pump.
proton pump a system for transporting protons across cell membranes, often exchanging them for other positively charged ions.
sodium pump (sodium-potassium pump) the mechanism of active transport driven by the energy generated by Na+,K+-ATPase, by which sodium (Na+) is extruded from a cell and potassium (K+) is brought in, so as to maintain the low concentration of sodium and the high concentration of potassium within the cell with respect to the surrounding medium. A high concentration of intracellular potassium is necessary for vital processes such as protein biosynthesis, certain enzyme activities, and maintenance of the membrane potential of excitable cells. Called also Na+-K+ pump.
stomach pump see stomach pump.
venous pump muscle pump.
molecular mechanism for the net transport of protons across a membrane; usually involves the activity of an ATPase.
proton pumpAn ATP-dependent H+ ion transporter present in the membranes of lysosomes and vacuoles, which maintains a low pH (4.5-5.0) inside these organelles. Proton pumping is also required in the electron transport chain, where an NADH (or FADH) is oxidised to NAD+ (or FAH+), releasing 2 electrons and a proton.
pro·ton pump(prō'ton pŭmp)
Molecular mechanism for the net transport of protons across a membrane; usually involves the activity of adenosine triphosphatase.
proton pumpa specialized assembly of proteins in a cell membrane which transports protons against a concentration gradient.
an elementary particle of mass number 1, with a positive charge equal to the negative charge of the electron; a constituent particle of every nucleus, the number of protons in the nucleus of each atom of a chemical element being indicated by its atomic number.
see sodium pump.
proton pump inhibitor
a class of therapeutic agents which are used to counteract the effects of proton pumps in tissues and organs, particularly used in counteracting gastric hypersecretion and acidity.