18 terms

bio osmosis and diffusion

hypertonic solution
a solution that causes a cell to shrink because of osmosis
isotonic solution
a solution whose solute concentration is equal to the solute concentration inside a cell
hypotonic solution
a solution that causes a cell to swell because of osmosis
the process by which a substance is released from the cell through a vesicle that transports the substance to the cell surface and then fuses with the membrane to let the substance out
the process when large particles are taken into the cell by endocytosis
the process when cells take up liquid from the surrounding environment
-tiny pockets form along the wall membrane, fill with liquid
then break off forming tiny vacuoles
the process of taking material into the cell by means off infoldings, or pockets, of the cell membrane
-the the outer of the pocets break lose from the outer of the cell membrane and form a vacuole within the cytoplam.
facilitated diffusion
molecules transported across a membrane in the direction of lowest concentration by a carrier protein
-does not require energy
-still driven by diffusion so a concentraion difference exisits across a membrane
passive transport
energy is not required for this process
contractile vacuole
rythemically pumps water out of the cell
osmotic pressure
tends to move water across membranes from a more dilute solution into a more concentated solution
diffusion of water through a selectively permeable membrane
selectively permiable
Only allows certain molecules through a membrane
occurs when the concentrations of the substances on both sides of the membrane are the same.
driving force behind movement of many substances across the cell membrane
-moelcules of a substance move from areas of high concentration to areas of low concentration
acive transport
energy requiring process that enables material to move across a cell membrane against a concentration difference
two types of active transport
active transport type 1
individual molecules are carried through membrane associated pumps
macromolecules that exsists in the cell membrane move molecules across the membrane
molecules that are transported:calcium
sodium and iron
these subastances are not normally able to diffuse across the membrane
requires chemical energy
active transport type 2
large amounts of materials are transported through movements of the cell membrane
one of the movements is called endocytosis
endocytosis then leads to phagocytosis