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Biology Ch. 5.1
Term | Definition |
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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 or another solvent from a more dilute solution (of a solute) to a more concentrated solution (of the solute) 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 | A solution whose solute concentration is equal to the solute concentration inside a cell |
Contractile Vacuole | In protozoans, 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 pore in a cell membrane through which ions can pass |