Lipid BilayerThe lipid bilayer is made of phospholipids thathave fatty acid chains.The polar molecules are located on the bottom ofthe bilayer.The non polar are located in the top of the bilayer.
DiffusionWhen two substances intermingle by themovement of their particles.Energy is not required for diffusion.
OsmosisA process in which molecules pass through asemipermeable membrane from a lessconcentrated solution to a more concentrated one;equalizing the two.
Facilitated DiffusionA type of passive transport that with the assistance of special proteins,substances are able to cross membranes.High concentration and low concentration areas need to be across the cellbarrier for facilitated diffusion to occur.During facilitated diffusion, substances can cross the lipid bilayer.
Active TransportThe movement of molecules across a cellmembrane into a place of higher concentration;energy is required.
ConcentrationThe relative amount of a substance in a certainspace.
Selective PermeabilitySelective Permeability is the property of amembrane that allows the cell to control whichsubstances can pass through the membrane.