Osmosis

• Osmosis occurs when water molecules move from an area of low solute concentration to an area of high solute concentration .
• A semi-permeable membrane allows some substances to pass through it, but not others.
• In osmosis, starch molecules cannot move through the membrane
• In osmosis, water molecules can move both ways through a membrane
• There will be more movement of water molecules in one direction until the solutions at both sides are of equal strength (equilibrium)
• In osmosis, on average, water molecules move from weak concentration to strong concentration
• osmosis requires diffusion
• selectively permeable membranes are ones that let some molecules through but not others
• osmosis can be stopped by applying pressure to more concentrated solution
• In osmosis, the movement through the membrane by water molecules is a random process
• though the movement of particles in osmosis random, water molecules are slightly more attracted to the more concentrated solution