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11 Cards in this Set
- Front
- Back
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Types of passive transport |
Simple diffusion: non polar molecules Facilitated diffusion: ionic polar molecules, water, glucose (Movement from high to low concentration) |
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Facilitated diffusion |
A special carrier protein with a central channel acts as a selective corridor which helps molecules move across the membrane
These special carrier molecules only bind to a specific molecule eg. a particular sugar or amino acid
Once a molecule binds to the carrier protein this protein changes shape to move the molecule down the concentration gradient, through the membrane into the cell. |
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Osmosis |
Net diffusion of water across a membrane toward a higher solute concentration When osmotic concentration is equal this is called isotonic A solution with a higher solute concentration is called hypertonic and the solution with lower solute concentration is called hypotonic |
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What are aquaporins |
Are integral membrane pore proteins They conduct water molecules in and out of the cell Prevent passage of other solutes Aka. Water channels |
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How to maintain osmosis balance |
Some cells use extrusion where water is ejected through contractile vacuoles There is also isomotic regulation and turgor |
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Active transport |
Charged ions Movement from low to high Uses carrier proteins/cell channelsRequires energy (ATP) to move materials against gradient. |
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What are the carrier proteins used in active transport |
Uniporters- move one molecule at a time Symporters- move 2 molecules in the same direction Antiporters-move 2 molecules in opposite directions |
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Coupled transport |
Uses ATP indirectly Uses the release of energy when a molecule moves by diffusion to supply energy to active transport of a different molecule Symporter is used |
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Endocytosis |
Movement of substances into the cell Plasma membrane surrounds and engulfs the food particles
Phagocytosis-cell takes in particular matter Pinocytosis-cell takes in only fluid RECEPTOR-MEDIATED ENDOCYTOSIS: specific molecules are taken in after they bind to a receptor |
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Exocytosis |
Movement of substances out of the cell Materials from the membrane-bound packages that migrate to the inner surface of the membrane fuse with the membrane and then release their contents to the outside of the cell. Requires energy (Used to secrete hormones, neurotransmitters, etc) |
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Bulk transport |
Large polar molecules are transported through endocytosis or exocytosis. |
