BIO304H5 Lecture Notes - Lecture 2: Electrophysiology, Membrane Potential, Resistor
Document Summary
The point at which you can make the action potential fire. A capacitor consists of two conductive plates (i. e. cytoplasmic and extracellular saline) separated by an insulator (the cell membrane) The plates must be close enough such that charges can sense" each other. Allows the buildup of charge and then immediately release the charges. No voltage flow because it can"t hold anymore. Opposite charges accumulate along opposing plates when a voltage is applied. Ions do not travel through the plates. Current results from repulsion/attraction of ions across the plates. Continue to charge until they match the applied voltage. Capacitors thus store voltage which is applied to them. Act like batteries, but can"t generate their own voltage. The ability of a capacitor to hold charges is defined by the equation. V is the electrical potential energy in volts. A system with large capacitance can store a lot of charge per unit volt. A simplified circuit diagram of the excitable cell.
