KINE 2011 Lecture Notes - Lecture 4: Electrochemical Gradient, Cell Membrane, Volt

• School: York University
• Department: Kinesiology & Health Science
• Course: KINE 2011
• Professor: Ali Abdul Sater

Document Summary

The movement of ions is not only driven by their concentration/permeability: electrical forces act upon these ions. Movement of ions across the membrane is determined by: 1. Electrical difference: create electrochemical gradient, this ca(cid:374) pote(cid:374)tially ge(cid:374)erate so(cid:373)e (cid:862)work(cid:863, thus, a separation of charges across the membrane = membrane potential, unit is millivolt (mv) or volt. Important point: these charges only represent a very small fraction of the total number of charged particles present in icf and ecf, which both remain neutral. The magnitude of potential depend on the # of opposite charges separated. How do the k+ and na+ cross the plasma membrane? protein (a-: they are water-soluble and therefore cannot diffuse across the plasma membrane, passive movements through protein channels. When the potassium equilibrium potential is reached: the plasma membrane has a potential, no net movement of k+ across the membrane, a large concentration of k+ still exists inside the cell.