GE CLST 73A Lecture Notes - Lecture 3: Depolarization, Electric Potential, Resting Potential

• School: UCLA
• Department: General Education Clusters
• Course: GE CLST 73A
• Professor: Chandler, S.H.

Document Summary

Voltage = the electric potential, charge separation. Membrane potential = voltage across the membrane. Resting potential = membrane potential at rest. Equilibrium potential = membrane potential if only one ion were permeable at rest. Which way the ion would flow if the membrane is permeable to it. Chem/electrical gradients change in size as ions move across the membrane. High permeability = high conductance = lots of open channels. Low permeability = low conductance = few open channels. These do not occur in real life. Action potential is due to the perturbation in the resting potential. Sodium channels are closed at resting potential: depolarizing force brings the membrane potential into the threshold, voltage-gated channels at threshold open. High concentrations of sodium outside, so it goes in. Each channel is sensitive to threshold: sodium channels inactivated, potassium channels open. When the potential is lower than the resting potential: all gated channels close, cells return to its resting potential.