Term
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Definition
Diffusion Pressure, ions move from higher concentration to lower concentraion.
No energy is required to move down concentration gradient |
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Term
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Definition
| Cations (positive charge) and Anions (negative charge) attracted to each other |
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Term
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Definition
| ease with which a molecule can move through a memebrane |
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Term
| When membrane is permeable to (+) and (-) ions |
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Definition
| concentration will equilibriate |
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Term
| When membrane impermeable to (+) & (-) ions |
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Definition
| Water will go into cell, swelling to minimize concentration difference |
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Term
| When membrane permeable to (-) not (+) ions |
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Definition
| since (+) attracts (-), (+) will try to keep (-) from leaving. Forces equal, but opposite, results in equilibrium |
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Term
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Definition
phospholipid bilayer - hydrophobic
membrane spanning proteins - create ion channels |
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Term
| properties of ion channels (list 3) |
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Definition
1) conduct ions
2) recognize and select specific ions
3) open and close in response to specificl electrical, mechanical, or chemical signals (note: some channels non-gated, always open) |
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Term
| Resting Equilibrium potentials for K, Na, Ca, and O |
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Definition
K: -80 mV
Na: 62 mV
Ca: 123 mV
o: -65 mV |
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Term
| concentration of K, Na, Ca, and O outside and inside of cell |
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Definition
K: 5 outside, 100 inside - 1:20
Na: 150 outside, 15 inside - 10:1
Ca: 2 outside, 0.0002 inside - 1:10,000
O: 150 outside 13 inside - 115:1 |
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Term
| equation for Rquilibrium potential |
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Definition
| E[ion]= (RT/ZF)*ln(concentration of ion outside/inside) |
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Term
| resting membrane potential of neuron |
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Definition
| -65 mV (due to more K channels open at rest, than Na channels) |
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Term
| Sodium-Potassium pump (Na-K pump) |
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Definition
| in order to keep stead resting membrane potential in cell, forces Na and K against concentration through use of ATP (uses as much as 70% of ATP utilized by brain |
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