What is active transport?

  • (noun): Transport of a substance (as a protein or drug) across a cell membrane against the concentration gradient; requires an expenditure of energy.

Active Transport

Active transport is the movement of a substance across a cell membrane against its concentration gradient (from low to high concentration). In all cells, this is usually concerned with accumulating high concentrations of molecules that the cell needs, such as ions, glucose and amino acids. If the process uses chemical energy, such as from adenosine triphosphate (ATP), it is termed primary active transport. Secondary active transport involves the use of an electrochemical gradient. Active transport uses cellular energy, unlike passive transport, which does not use cellular energy. Active transport is a good example of a process for which cells require energy. Examples of active transport include the uptake of glucose in the intestines in humans and the uptake of mineral ions into root hair cells of plants.

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Some articles on active transport:

Active Transport - Endocytosis
... Biologists distinguish two main types of endocyctosis pinocytosis and phagocytosis ... In pinocytosis, cells engulf liquid particles (in humans this process occurs in the small intestine, cells there engulf fat droplets) ...
Diel - Importance With The Biological Pump
... This is something known as active transport ... The organisms are playing a more active role in moving organic matter down to depths ... Zooplankton and salps play a large role in the active transport of fecal pellets ...
Secondary Active Transport
... In secondary active transport, also known as coupled transport or co-transport, energy is used to transport molecules across a membrane however, in contrast to primary ...
Secondary Active Transport - Details
... trans-membrane proteins recognize the substance and allows it access (or, in the case of secondary transport, expend energy on forcing it) to cross the membrane when it otherwise would not, either because it ... The last case, known as primary active transport, and the proteins involved in it as pumps, normally uses the chemical energy of ATP ... exploitation of an electrochemical gradient, are known as secondary active transport and involve pore-forming proteins that form channels through the cell membrane ...
Membrane Transport - Transport Types - Active Transport and Co-transport
... In active transport a solute is moved against a concentration or electrochemical gradient, in doing so the transport proteins involved consume metabolic energy ... In primary active transport the hydrolysis of the energy provider (e.g ... ATP) takes place directly in order to transport the solute in question, for instance, when the transport proteins are ATPase enzymes ...

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