concentration gradient


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Related to concentration gradient: active transport, Facilitated diffusion

den·si·ty gra·di·ent

a solution in which the concentration (density) of a solute increases in a continuous fashion from top to bottom, or end to end, of a container (for example, the centrifuge tube in density-gradient centrifugation).

concentration gradient

The difference in the amounts of a substance on either side of a membrane or in two areas of a biological system. Substances diffuse down a concentration gradient, from the area of higher concentration to lower concentration.
See also: gradient

concentration gradient

a system that is set up where the concentration of any SUBSTRATE (usually in the form of ions or molecules) is different with respect to the concentration elsewhere in the system. For example, ionic concentration across cell membranes, solutes in sap.
References in periodicals archive ?
Dexamethasone levels and base-to-apex concentration gradients in the scala tympani perilymph after intracochlear delivery in the guinea pig.
[29] that a concentration gradient can either increase or decrease the tendency towards DDT with the decisive factor being the obstacle geometry.
It is presumed that the average diffusion distance x is proportional to the tubulin concentration gradient length L; then
Influence of pH and Concentration Gradient on the Tunable Ionic Current Rectification Performances.
The model took into account both the diffusion under concentration gradient and potential gradient and active transport which was ATPase enzyme mediated, and appropriate partial differential equations for the two mechanisms of transport had been derived and were solved by iterative methods.
The heat and mass transfer rates at the wall are related to the temperature and concentration gradients at the wall are, respectively,
The slowly crystallizing polymer with the highest molecular mass, being closest to its equilibrium melting point, cannot form spherulites anymore, owing to the high concentration gradient of salt in the amorphous surrounding (Fig.
2,1 entails an interesting conclusion: regardless of the aforesaid effects related to [delta]m that possibly alter the plain diffusion process, the time evolution of the system is actually consequence of the concentration gradient law; although the Fick hypothesis does not contain explicit reference to the time, this latter enters indeed into the problem through v.
This innate electrical signaling system regulates bodily functions from the cellular level by using the movement of ions with a small positive or negative electrical charge to create concentration gradient and consequently an electric potential gradient.
Such system becomes unstable when heated from below and generates solute concentration gradient known as the Soret effect, which is characterized by the separation parameter N, proportional to the thermodiffusion coefficient.
Concentration gradient: For a gas or liquid, diffusion occurs where there is a difference in pressure or concentration between two different areas.
Most commonly, a chemical source well created an attractant concentration gradient via diffusion into an observation arena (8-11).

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