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16 Cards in this Set
- Front
- Back
Transport Proteins |
A transmembrane protein that helps a certain substance or class of closely related substances to cross the membrane |
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Aquaporins |
A transport protein in the plasma membrane of a plant or animal cell that specifically facilitates the diffusion of water across the membrane (osmosis) |
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Diffusion |
The spontaneous tendency of substance to move down its concentration gradient from a more concentrated to a less concentrated area |
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Concentration Gradient |
An increase or decrease in density of a chemical substance in an area. Cells often maintain this with ions across their membranes. |
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Passive Transport |
The diffusion of a substance across a biological membrane. |
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Osmosis |
The diffusion of water across a selectively permeable membrane |
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Tonicity |
The ability of a solution to cause a cell within it to gain or lose water |
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Isotonic |
Having the same solute concentration as another solution |
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Hypertonic |
In comparing two solutions, referring to the one with a greater solute concentration |
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Osmoregulation |
How organisms regulate solute concentrations and balance the gain and loss of water |
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Turgid |
A walled cell becomes this if it has a greater solute concentration than its surroundings, resulting in the entry of water |
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Flaccid |
A walled cell is this when in surroundings where there is no tendency for water to enter |
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Plasmolysis |
To shrink and pull away from a cell wall, or when a plant cell protoplast pulls away from the cell wall as a result water loss |
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Facilitated Diffusion |
The spontaneous passage of molecules and ions, bound to the specific carrier proteins, across a biological membrane down their concentration gradient |
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Ion Channels |
Protein channel in a cell membrane that allows a passage of a specific ion down its concentration gradient |
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Gated Channels |
A protein in a cell membrane that opens and closes in response to a particular stimulus |