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Passive Transport
Unit 2, Chapter 5, Section 1, Diffusion and Osmosis
| Term | Definition |
|---|---|
| Passive Transport | the movement of substances across a cell membrane without the use of energy by the cell |
| Diffusion | the movement of particles from regions of higher density to regions of lower density |
| Concentration Gradient | a difference in the concentration of a substance across a distance |
| Equilibrium | in biology, a state that exists when the concentration of a substance is the same throughout a space |
| Osmosis | the diffusion of water from a more dilute solution to a more concentrated solution through a membrane that is permeable to the solvent |
| Hypotonic | describes a solution whose solute concentration is lower than the solute concentration inside a cell |
| Hypertonic | describes a solution whose solute concentration is higher than the solute concentration inside a cell |
| Isotonic | describes a solution whose solute concentration is equal to the solute concentration inside a cell |
| Contractile Vacuole | an organelle that accumulates water and then releases it periodically to maintain osmotic pressure |
| Turgor Pressure | the pressure that is exerted on the inside of cell walls and that is caused by the movement of water into the cell |
| Plasmolysis | the contraction or shrinking of the cell membrane of a plant cell in a hypertonic solution in response to the loss of water by osmosis |
| Cytolysis | the bursting of a cell |
| Facilitated Diffusion | the transport of substances through a cell membrane along a concentration gradient with the aid of carrier proteins |
| Carrier Protein | a protein that transports substances across a cell membrane |
| Ion Channel | a complex of protein molecules in a cell membrane that for a pore through which ions can pass |