membrane potential Flashcards
what is membrane potential?
It is a potential gradient that forces ions to move in one direction.
Membrane potential(Vm) is the voltage difference that occurs across the plasma membrane.
What is the membrane potential at rest?
-70mV
What is the ECF?
Extracellular fluid
What is the ICF?
Intracellular Fluid
Why is active transport important ?
Maintains normal ionic concentration (concentration gradient and movements of other solutes across the membrane)
Indirectly determines cellular gradients of other ions and molecules(secondary active transport).
What is the Equilibrium potential (Eion)?
It’s the point at which an ion can maintain equal aand opposite forces.
Can be determined using Nernst equation.
What is the Nernst Equation?
What is typically th eequilibrium potention of potassium?
-90mV
What is typically th eequilibrium potention of Sodium?
60mV
What would happen if the membrane was only permeable to sodium ions?
The resting membrane potential woud be 60mV.
What would happen if the membrane was 40x more permeable to potassium ions than sodium ions?
It woul dbe closer to Equilibrium of potassium(Ek), but not exactly Ek as there would be some permeablility to sodium via leaked channels, allowing sodium ions to move in.
What is the Goldmann equatin and use of it?
What is the use of the Sodium potassium ATPase?
Helps maitain the concentration gradient (higher levels of potassium inside the cell and higher levels of sodium ouside the cell).
