Energy-requiring transport of solutes across cell membranes, against the prevailing concentration gradient.
Cell-mediated, energy-requiring translocation of a molecule across a membrane in the direction of increasing concentration (i.e., opposite of natural tendency).
In physiology, an energy- producing process by which certain nutrients are pumped from one compartment to another against a concentration gradient.
Active transport is a process whereby a substance moves from one side of a cell to the other, as in the absorption of several nutrients. This process requires energy from adenosine triphosphate (ATP) and a carrier molecule. Nutrients absorbed via active transport can be absorbed against a concentration gradient.
Carrying of a substance (e.g. drug, amino acid) across a cell membrane against the concentration or pressure gradient, requiring the expenditure of energy.
An energy-dependent process in which certain substances (including ions, some drugs, and amino acids) are able to cross cell membranes against a concentration gradient. The process is inhibited by substances that interfere with cellular metabolism (e.g. high doses of digitalis).
The process by which a cell membrane moves molecules against a concentration or electrochemical gradient. This requires metabolic work. Potassium, for example, is maintained at high concentrations within cells and low concentrations in extracellular fluid by active transport. Other ions actively transported are sodium, calcium, hydrogen, iron, chloride, iodide, and urate. Several sugars and the amino acids are also actively transported in the small intestine.