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A concentration gradient is a measure of the difference in solute concentration between two points in space or over time. It is quantified as the change in solute concentration per unit distance or time. The steepness of the concentration gradient indicates the rate at which the solute is diffusing. A steeper gradient indicates a higher rate of diffusion, while a shallower gradient indicates a lower rate of diffusion. Concentration gradients are the primary driving force for diffusion, which is the process by which molecules move from an area of higher concentration to an area of lower concentration in order to reach equilibrium.
Concentration gradients are important in many biological processes, including the movement of water and solutes across cell membranes, the transport of nutrients and waste products in the body, and the diffusion of gases in the lungs. Concentration gradients also play a role in the development of certain diseases and conditions, such as kidney failure and diabetes.