passive transport
the movement of materials across the plasma membrane, down a concentration gradient, that does not require energy
diffusion
passive transport of molecules down a concentration gradient (area of high concentration to low concentration)
concentration gradient
difference in solute concentrations between two adjacent regions
kinetic energy
the energy an object has due to its motion
solute
substance that is dissolved in a solvent.
solvent
the substance in which a solute a dissolved in (dissolving medium)
facilitated diffusion
diffusion of substances across a cell membrane along a concentration gradient with the aid of membrane proteins
protein channel/channel protein
transmembrane protein pore in the phospholipid bilayer that selectively enables the transport of large/polar molecules
carrier protein
membrane transport protein which undergoes conformational change to passively transport materials across a membrane
conformational change
temporary change to the structure/shape of a macromolecule that allows materials to cross through
osmosis
passive diffusion of water from areas of low solute concentration to high solute concentration
osmolarity
measure of total solvent particles in a solute
tonicity
the ability of a solution to cause a cell to gain or lose water - measure of concentration of solutes on either side of a membrane
hypertonic
having a higher solute concentration than another solution
hypotonic
having a lower solute concentration than another solution
isotonic
having an equal solute concentration as another solution
turgid
(plant cells) swollen/firm due to high water content
plasmolysis
(plant cells) with weak and sagging membranes due to a lack of water
flaccid
(plant cell) soft/loose cell lacking turgidity - isotonic solutions
lyse
the bursting of the cell membrane (due to high intracellular water content)
ion
charged atom - positive or negative charge.
aquaporin
channel/transport protein, that facilitates the passive transport of water
turgor
(plant cells) cell wall pressure generated when the contents of the cell press against the cell wall. regulates water content and protects the cell - prevents lysis