Chapter+5+Vocab

Passive transport - the movement of substances across a cell membrane without the use of cell energy Diffusion - the process by which molecules move from an area of greater concentration to an area of lesser concentration Concentration gradient - the difference in concentration of a substance across space Equilibrium - a state that exists when the concentration of a substance is the same throughout the space Osmosis - the diffusion of water across a selectively permeable membrane active transport - moving particles from areas of lower concentration to high concentration endocytosis - the process in which cells ingest external fluid, macromolecules, large molecules and other cells vesicle - a membrane bound organelle that forms a pouch around a particle phagocytosis - the movement of large molecules or whole cells turgor pressure - water pressure within a plant cell carrier protein - a protein that transports specific substances across a biological membrane plasmolysis - the shrinking or wilting of a walled cell in a hypertonic environment cytolysis - the bursting of a cell hypotonic - describing a solution whose solute concentration is lower than that inside a cell hypertonic - describing a solution whose solute concentration is higher that that inside a cell isotonic - describing a solution whose solute concentration equals that inside a cell facilitated diffusion - a process in which substances move down their concentration gradient, across the cell membrane with the assistance of carrier proteins pinocytosis - a type of endocytosis in which a cell engulfs solutes or fluids contractile vacuole - an organelle in protists that expels water ion channels - a membrane protein that provides a passageway across the cell membrane through which and ion can diffuse exocytosis - vesicles in the cytoplasm fuse with the cell membrane, releasing their contents into the cell's external environment phagocyte - a cell that engages in phagocytosis sodium-potassium pump - a carrier protein that actively transports K+ ions into cells and Na+ ions out of cells