Active Ion Transport

Active Ion Transport

 

in biology, the migration of ions (sodium, potassium, magnesium, calcium, and others) in living systems through various cellular membranes (for example, nerve and muscle cells, erythrocytes, and others) against a concentration gradient, solubility gradient, electroosmotic gradient, or other gradients, using the energy of metabolic processes accumulated in the system of adenosinephosphoric acids (primarily adenosine triphosphate) and other macroenergetic—that is, energy-rich—compounds. The decay of one molecule of adenosine triphosphate is usually accompanied by transport of two or three nonvalent cations or one bivalent cation. The primary enzyme responsible for converting energy into work that transports ions is adenosine triphosphate, which is concentrated in biological membranes and is activated by the presence of sodium, potassium, and magnesium ions and lipides. One particular case of this enzyme’s action is the energy supply for active ion transport (primarily of sodium ions) through nerve cell membranes.

A. A. BOLDYREV

References in periodicals archive ?
One possible explanation is compensation of minor ion leakage by active ion transport. At the organ of Corti in the cochlea of Tric-/- mice, the minor leakage of K+ from endolymph to perilymph is presumed to be the trigger of eventual hair cell degeneration [10].
The extensive plasma membrane infoldings associated with mitochondria provide increased surface area and energy for active ion transport. Similar ultrastructural features are exhibited by transporting epithelia throughout the animal kingdom (Berridge & Oschman 1972).
The relative roles of passive surface forces and active ion transport in the modulation of airway surface liquid volume and composition.
Previous studies from our laboratory have shown that the third isoform of metallothionein (MT-3), a unique member of metallothionein family is involved in the maintenance of vectorial active ion transport in cultures of human proximal tubule (HPT) cells [2].
Previous work from this laboratory has implicated the expression of the third isoform of metallothionein (MT-3) in the maintenance of proximal tubular vectorial active ion transport as evidenced by the formation of domes.

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