OSMOSIS

=Osmosis= '''Osmosis is the diffusion of water across a selectively-permeable membrane''' [image:http://i.imgur.com/NxPnH96.png] The cell membrane is selectively permeable - this means that it only lets certain things across. In the example above, the membrane does not allow the movement of the solute (e.g. sugar) across the membrane. However, water is able to more freely across the membrane. Water will diffuse from an area of high water concentration to an area of low water concentration. Because the presence of the solute (e.g. sugar) effectively lowers the concentration of water, water molecules will move from left to right down its concentration gradient.