| A | B |
|---|
| carrier protein | a protein that transports specific substances across a biological membrane |
| concentration gradient | the difference in concentration of a substance across space |
| contractile vacuole | an organelle in protists that expels water |
| cytolysis | the bursting of a cell |
| diffusion | the process by which molecules move from an area of greater concentration to an area of lesser concentration |
| equilibrium | a state that exists when the concentration of a sibstance is the same throughout a space |
| facilitated diffusion | a process in which substances move down their concentration gradient across the cell membrane with the assistanceof carrier proteins |
| hypertonic | describing a solution whose solute concentration is higher than that inside a cell |
| hypotonic | describing a solution whose solute concentration is lower than that inside a cell |
| ion channel | a membrane protein that provides a passageway across the cell membrane through which an ion can diffuse |
| isotonic | describing a solution whose solute concentration equals that inside a cell |
| osmosis | the diffusion of water across a selctively permeable membrane |
| passive transport | the movement of substances across a cell membrane without the use of cell energy |
| plasmolysis | the shrinking or wilting of a walled cell in a hypertonic environment |
| turgor pressure | water pressure within a plant cell |
| active transport | the movement of a substance across a cell membrane a concentration gradient; requires the cell to expend energy |
| endocytosis | the process by which a cell surrounds and engulfs substances |
| phagocyte | a cell that engages in phagocytosis |
| phagocytosis | a type of endocytosis in which a cell engulfs large particles or whole cells |
| pinocytosis | a type pf endocytosis in which a cell engulfs solutes or fluids |
| sodium potassium pump | a carrier protein that actively transports K+ ions into and Na+ ions out of cells |
| vesicle | a membrane bound sac in a eukaryotic cell that contains materials involved in endocytosis, exocytosis, or transport within the cell |
| exocytosis | a process in which a vesicle inside a cell fuses with the cell membrane and releases its contents to the external environment |
