Term
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Definition
membrane potential at which the electrical driving force is equal and opposite to the chemical driving force
-electrochemical driving force is zero
-larger concentration gradient mean larger equilibrium potentails becasue a greater electrical force is required to balance the larger concentration gradient |
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Term
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Definition
(61mV / z) * log([I]o / [I]I) = mV
z-charge
[I]-concentration of in and out of cell |
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Term
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Definition
–The rate at which a substance is transported across a membrane
–Refers to the number of molecules that cross the membrane in a given length of time |
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Term
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Definition
| the net movement of molecules across the membrane. |
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Term
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Definition
–Describes the passive transport of molecules through a biological membrane’s lipid bilayer
–The mechanism of simple diffusion is not strictly biological. |
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Term
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Definition
| measure of the ease with which molecules are able to move through the cell membrane. |
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Term
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Definition
The rate of transport is in direct proportion to the surface area of the membrane.
–This is true regardless of the mechanism of transport we are looking at.
•Many tissues take advantage of this by using folding and branching to increase surface area. |
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Term
| Frick's Law of Diffusion Applied to Membranes |
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Definition
Net flux = PA (DeltaC)
–P is permeability
–A is area
– DeltaC is concentration gradient |
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Term
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Definition
–The passive movement of molecules from one location to another as a result of their own thermal motion.
–Random thermal motion |
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Term
| Three factors impact a substance when it is transported across a membrane by simple diffusion. |
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Definition
–The magnitude of the driving force.
–The membrane surface area.
–The permeability of the membrane |
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