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Diffusion/Osmosis
Term | Definition |
---|---|
Diffusion | he movement of molecules from an area of high concentration to an area of low concentration. Does not require energy. |
Osmosis | the diffusion of water across a selectively perimeable membrane. |
Solute | the substance that is dissolved in a solvent |
Solvent | substance in which a solute is dissolved |
Solution | solutes dissolved in solvent |
Concentration | mass of solute in a given volume of solution |
Concentration gradient | a difference in concentration in one place compared to another |
Equilibrium | the solute concentration is uniform or equal everywhere in the solution. |
Permiable | all molecules can cross the membrane |
Semipermiable | only certain molecules can cross the membrane, others cannot cross |
Selectively permeable | only certain molecules can cross the membrane, others cannot Impermeable - nothing can cross the membrane |
Passive transport | movement across the membrane that does not require energy. Includes diffusion, osmosis, facilitated diffusion, and protein channels |
Active transport | movement across the membrane that requires energy. Includes pumps and vesicles |
Isotonic | the solute concentration inside the cell is the same as the solute concentration outside the cell |
Hypertonic | Solute concentration outside cell is greater than inside cell. Cell will shrink. |
Hypotonic | solute concentration outside cell is less than inside the cell. Cell will swell. |
Vesicles | are small membrane sacs that pinch off of cell membranes |
Endocytosis | vesicles used to bring materials into the cell. Uses ATP |