Term
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Definition
the solution outside the cell is hypotonic, means that the
concentration of solute is higher inside the cell, therefore water enters the cell and the cell
swells. |
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Term
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Definition
the solution outside the cell is hypertonic, means that the
concentration of solutes is lower inside the cell, therefore water leaves the cell and the
cell shrinks. |
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Term
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Definition
The process of crossing a membrane DOWN a concentration gradient with the aid of a carrier protein,
eg glucose, amino acids and iron. Does NOT require energy input. |
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Term
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Definition
process of crossing a membrane AGAINST a concentration gradient with the aid of a carrier
protein. DOES require energy input.
This is necessary when the cell needs more of a nutrient it already has quite a lot of; or
when the cell wants to get rid of something that there is already more of outside the cell. |
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Term
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Definition
Transports large particles out of cells.
Vesicles move to the cell membrane, fuse with it and then release contents out of the cell. |
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Term
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Definition
Transports large particles into the cell.
The cell membrane enfolds and pinches off a vesicle into the cell, bringing particles from outside
with it. |
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Term
| Receptor-mediated Endocytosis |
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Definition
A receptor protein on the cell surface is bound by a particular biochemical called a ligand. The cell
membrane then indents and endocytoses the ligand-bound receptor. Receptor-mediated endocytosis enables
liver cells to bind and take in dietary cholesterol from the blood. |
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