BIOL 2021 Lecture Notes - Lecture 5: Conformational Change, Cytosol, Neuromuscular Junction
26 Jan 2017
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1) voltage gated: open and close depending on the voltage of the membrane, open when voltage across membrane changes. 2) ligand gated: open when a specific molecule specific for that particular ion channel open, ex: neurotransmiiter, protein etc, can be extracellular or intracellular. 3) mechanically gated: opens when under mechanical stress, something will attach and physically pull the channel open find them in very specialized tissues. Definition: difference in electrical charge across a membrane. Mainly the plasma membrane (outside membrane of all cells) plasma membrane in all cells have a potential. Something that causes a membrane potential in animal cells is called electrogenic: na+/k+ pump pumps out 3 na+ and in 2 k+, creating an imbalance in charge. This causes a na+ gradient that can be used. Only contributes to 10% of potential: k+ leak channels (there are several kinds) If you leave cell alone, it comes to k+ equilibrium.
