BIOL273 Chapter Notes - Chapter 3: Resting Potential, Nernst Equation, Extracellular Fluid
Document Summary
The main chemical players that make up our bodies: na+, cl-, k+, ca2+ Na+,cl- and ca2+ are more concentrated in extracellular fluid, k+ more concentrated in cytoplasm. Resting membrane potential: the different in voltage across the membrane when a cell is at rest. What affects resting membrane potential: the concentration of ions, and the permeability of the membrane to that ion. Hyperpolarization: positive charge lost from cell, cell becomes more negative. Repolarization: when a channel returns to its normal state. Equilibrium potential: can calculate the electrical potential of cell needed to generate an equilibrium state for any ion using the nernst equation (if you know concentration gradient). Ghk equation is better to use if multiple ions. Gated ion channels: regulate the movement of ions, determine whether or not an ion will pass through. Mechanically gated: found in sensory neurons, need physical force. Chemical gated: chemical binds to channel such as neurotransmitters, neuromodulators, etc, changes conformation of channel.