Term
| Are cells negatively or positively charged compared to the ECF? |
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Definition
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Term
| What is the resting potential of a cell? |
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Definition
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Term
| Where is the potential charge of a cell? |
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Definition
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Term
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Definition
I=V/R
Current=Potential/Resistance |
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Term
| Do membranes have a high or low electrical resistance? |
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Definition
| High, because of the lipids in the membrane |
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Term
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Definition
1/R
Measures how easily an ion can cross the cell membrane and affect its charge |
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Term
| Why does a cell's conductance change? |
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Definition
| Ion channels open and close |
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Term
| Are cations positive or negatively charged? What about anions? |
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Definition
| Cations are positive, anions are negative |
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Term
| Define electrochemical potential |
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Definition
| The algebraic sum of the electrical and chemical forces |
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Term
| Define equilibrium potential |
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Definition
| When the driving force of the concentration gradient for the ion is equal and opposite to the electrical force on the ion and thus there is no net movement of the ion across the membrane |
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Term
| What is the equilibrium potential for K+? |
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Definition
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Term
| What is the equilibrium potential for Na+? |
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Definition
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Term
| What is the equilibrium potential for Cl-? |
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Definition
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Term
| What is the importance of the chord conductance equation? |
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Definition
| It shows how multiple ions affect the membrane potential of a cell |
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Term
| Which has a higher conductance, K+ or Na+? Why? |
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Definition
At rest, K+ has a conductance of about 50x higher
Because there are many more leak channels for K+ |
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Term
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Definition
| decreased membrane potential, less negative, more positive |
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Term
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Definition
| Increased membrane potential, more negative, less positive |
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Term
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Definition
| return of membrane potential to its resting level |
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Term
| When does conductance of an ion change? |
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Definition
| When a channel is opened or closed |
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Term
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Definition
A measure proportional to the membrane potential minus the equilibrium potential for that ion
A higher driving force leads to larger current carried by that ion |
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Term
| When considering if an ion will move across a membrane, do you take into account molarity or electric potential? |
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Definition
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