2. What is diffusion? When molecules move from an area where there are many of them, to an area where there are fewer of them E.g. molecules of food coloring spreading out in the beakers This happens in liquids and gases E.g. spraying perfume It is a form of passive transport Does not need to use cell energy to enter the cell
3. Diffusion continued… When the molecules are equally or evenly spread out, this is called EQUILIBRIUM EQUAL amounts = Equilibrium The molecules move until they reach equilibrium, and they keep moving to maintain equilibrium
4. Diffusion into a cell Diffusion into a cell has to cross the ____cell membrane___________________ Cell membranes are selectively permeable SELECTS (chooses) what to let in Water is necessary for all life and all of your cells, so how does it enter across the cell membrane? OSMOSIS! It is the diffusion of water across a cell membrane
