Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Sodium Potassium Pump
Document related concepts
Cell growth wikipedia , lookup
Node of Ranvier wikipedia , lookup
Signal transduction wikipedia , lookup
Chemical synapse wikipedia , lookup
Organ-on-a-chip wikipedia , lookup
Mechanosensitive channels wikipedia , lookup
Cytokinesis wikipedia , lookup
Circular dichroism wikipedia , lookup
Action potential wikipedia , lookup
Cell membrane wikipedia , lookup
Endomembrane system wikipedia , lookup
Transcript
Nature of Nerve Signals Nature of Nerve Signals changes in ion concentration across the plasma membrane = voltage voltage = electrical potential energy neurons are electrically polarized one side has a different charge than the other + + + + + + + + + - - - - - - - - - - - - - - - - + + + + + + + + + electrically polarized @ rest more negatively charged on inside than the outside electrically polarized the charge difference is basically like a battery!! electrically polarized the charge difference is measured with an oscilloscope electrically polarized the charge difference is measured with an oscilloscope Since plasma membranes are made of phospholipids, ions (because they are electrically charged) cannot dissolve & diffuse across the membrane. As it turns out, neurons have a much greater # of ion channels for K+ than they do for Na+… more K+ pumps + + + + + + + + + - - - - - - - - - - - - - - - - + + + + + + + + + electrically polarized @ rest more negatively charged on inside than the outside these are always open (K+) & (Na+), keep the resting potential [Na+] [K+] these particular ion channels are always OPEN… open ungated channels [Na+] [K+] Sooo, K+ LEAVES the cell. [Na+] [K+] Sooo, K+ LEAVES the cell. while + Na trickles into the cell. [Na+] This causes a voltage differential [K+] Sooo, K+ LEAVES the cell. while + Na trickles into the cell. [Na+] [K+] resulting in a resting voltage potential [Na+] [K+] -70 mV the inside of the cell is 70 mV more negative than the outside resting potential resting potential As it turns out, having a action potential membrane potential is a GOOD THING when it comes to neurons!! [Na+] [K+] -70 mV Why don’t the charges move to equilibrium? [Na+] [K+] -70 mV sodium-potassium pump Types of Active Transport 1. Carrier-Mediated ANIMAL EXAMPLE: Na+ - K+ pump active transport carrier proteins in cell interior more Na+ pumped out, than K+ pumped in more Na+ pumped out, than K+ pumped in Clip Ch. 48 Resting Potential herex Go back to membrane ppt.
