BIOL 201 Lecture Notes - Lecture 25: Nernst Equation, Resting Potential, Goldman Equation

• School: McGill University
• Department: Biology
• Course: BIOL 201
• Professor: Gary Brouhard

Document Summary

Synaptic signals: from receptors, directly respond to stimuli, from other neurons. Add together to depolarize past the membrane threshold: active signal: Establishing the membrane potential: established by the na/k atp-pump in neurons that exports 3 sodium for every 2, channels let ions pass down from concentration gradient potassium entering. Electrochemical equilibrium between charge (electric) and concentration on either side of membrane. Equilibrium of species all by themselves can be calculated using the nernst equation: This is due to the net negative charge on the inside of the membrane, vs the net positive charge on the outside of the membrane. More than one species: calculate membrane voltage using goldman equation: (cid:3017)(cid:3260)(cid:3126)[(cid:3012)(cid:3126)(cid:3284)(cid:3289)](cid:2878)(cid:3017)(cid:3263)(cid:3276)(cid:3126)[(cid:3015)(cid:3028)(cid:3126)(cid:3284)(cid:3289)](cid:2878)(cid:3017)(cid:3252)(cid:3287)(cid:3127)[(cid:3004)(cid:3039)(cid:3127)(cid:3290)(cid:3296)(cid:3295)](cid:4673) We get a resting v of around -60 mv: p is the permeability of the membrane to ionic species, relative permeabilities (rest) k:na:cl = 1. 0 : 0. 04 : 0. 45. Mcgill university biol 201 prof. gary brouhard: there is a huge driving force on sodium (equ.