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An electrochemical gradient is a gradient of electrochemical potential, usually for an ion that can move across a membrane. The gradient consists of two parts: The chemical gradient, or difference in solute concentration across a membrane. The electrical gradient, or difference in charge across a membrane.
Fick's first law relates the diffusive flux to the gradient of the concentration. It postulates that the flux goes from regions of high concentration to regions of low concentration, with a magnitude that is proportional to the concentration gradient (spatial derivative), or in simplistic terms the concept that a solute will move from a region of high concentration to a region of low ...
is the gradient, i.e., rate of change with position, of the logarithm of the salt concentration, which is equivalent to the rate of change of the salt concentration, divided by the salt concentration – it is effectively one over the distance over which the concentration decreases by a factor of e. The above equation is approximate, and ...
Concentration gradients can develop relatively quickly and persist for a long time in the system; Chemotactic and chemokinetic activities are distinguished; Migration of cells is free toward and away on the axis of the concentration gradient; Detected responses are the results of active migration of cells
A change in concentration over a distance is called a concentration gradient, a change in pressure over a distance is called a pressure gradient, and a change in temperature over a distance is called a temperature gradient. The word diffusion derives from the Latin word, diffundere, which means "to spread out".
First, concentration changes in the solution reduce the driving force within the membrane, hence, the useful flux/rate of separation. In the case of pressure driven processes, this phenomenon causes an increase of the osmotic pressure gradient in the membrane, which reduces the
An ion gradient has potential energy and can be used to power chemical reactions when the ions pass through a channel (red). Hydrogen ions, or protons, will diffuse from a region of high proton concentration to a region of lower proton concentration, and an electrochemical concentration gradient of protons across a membrane can be harnessed to ...
This unequal distribution results in a concentration gradient that drives the dispersion of particles in the medium so that the concentration is constant across the entire bulk. With respect to convection, variations in velocity between flow paths in the bulk facilitate the distribution of the dispersed material into the medium.