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Explain osmosis?
Large quantities of water molecules constantly move across cell membranes by simple diffusion, but, in general, net movement of water into or out of cells is negligible. There are, however, many cases in which net flow of water occurs across cell membranes and sheets of cells. An example of great importance to you is the secretion of and absorption of water in your small intestine. In such situations, water still moves across membranes by simple diffusion, but the process is important enough to warrant a distinct name - osmosis. Osmosis is the net movement of water across a selectively permeable membrane driven by a difference in solute concentrations on the two sides of the membrane. A selectively permeable membrane is one that allows unrestricted passage of water, but not solute molecules or ions.


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