BILD 26 Lecture Notes - Lecture 2: Electrochemical Gradient, Active Transport, Bowstring
Document Summary
The general process is as described: o some form of stimulus triggers the movement of ions across the membrane by possibly opening some of the ion channels. o since there is a higher concentration of sodium outside of the cell, upon the opening of the channel sodium rushes in, bring in positive charge with them. o the influx of sodium causes the membrane potential to get more positive (from 70 mv towards 0), a process known as depolarization. Na+ channel na+ enters amplifies depolarization. o on the other hand, opening of k+ channel utilizes negative feedback loop: depolarization open k+ channel k+ leaves cell cancels depolarization (makes cell more negative) o na+ channels open quickly, while k+ channels open slowly o action potentials are conducted all the way to axon terminals without the loss of amplitude. o summary (see diagram):
