*Passive transport:the movement of materials across the cell membrane without using cellular energy.
-one of the most important functions of the cell membrane is to keep the cell's internal conditions relatively constant
*diffusion:is the process by which particles move from an area of high concentration to an area of lower concentrations, is the driving force behind the movement of many substance across the cell membrane, not require the cell to use energy,depend on random particle movements
*equilibrium: is the state in which a process and its reverse are occurring at equal rates so that no over all change is taking place
*facilited diffusion: this procces, in which molecules that cannot directly diffuse across the membrane pass through special protein channels, is fast and specific, it does not require any additional use of the cell's energy.
^osmosis: is the diffusion of water through a selectively permeable membrane,in osmosis, as in other forms of diffusion, molecule move from an area of higher concentration to an area of lower concentration the molecules that move in the case of osmosis are water molecules.
^isotonic: "same strength"
^Hypotonic:" below strength"
*osmotic pressure: the net movement of water out of or into a cell produces a force known
*Proteins pomps: energy from atp is used to pump small molecules and ions across the cell membrane active transport protein changes shape during the process,binding substance on one side of the membrane,and releasing them on the other