IMED1001 Study Guide - Final Guide: Osmotic Concentration, Tonicity, Solution
Document Summary
Explain the importance of osmolarity, tonicity and membrane permeability for cell volume regulation. Explain the distinction between the terms isotonic and isosmolar. List reasonable values of normal extracellular and intracellular osmolarity. An important mechanism by which many substances, including water, get into and out of cells. And this means that there is a net statistical tendency for molecules of a particular substance. To move from regions of high concentration to regions of low concentration. This net movement down a concentration gradient is called. Does not require the input of energy from some external source. The movement is said to be downhill . Because it occurs down the concentration gradient. And it requires no expenditure of metabolic energy, provided a concentration gradient exists. The rate of passive diffusion of an uncharged substance is. Directly dependent on the concentration gradient and can be described by. S/ t = d ( c/ x) ---------------- (1)
