5-Elec Signals Neurons Figs BW

all potassium channels have common structure and

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: arization (all of them, i think)*** some close at depolarization, open at hyperpolarize, close at depo. important in function of heart Anderson, PAV & Greenberg, RM (2001) Comp Biochem Physiol B Biochem Mol Biol 129:17-28. here's a big alpha subunit with 4 link domains. there are also one or more associated beta subunit (2 here).each of 4 domain represent a large gush. beta subunit is associated with outside the channel. don't have to memorize. the function of the V-Na is related to location particular amino acid. also have certain phosphorylation site that change property of sodium channel. Voltage-Gated Na+ Channel (Nav) α β2 β1 Selectivity Filter Yu & Catterall (2003) Genome Biology 4:207 Modulation Yu & Catterall (2003) Genome Biology 4:207 1/29/14 In the Inner Ear: a) what is approx. value of Ek across the apical membrane? b) if K+ channels open in the apical membrane, will K+ flow into or out of the cell? - I=g(Vm*Ek) c) would the current in b hyperpolarize or depolarize the cell? Recording from Single K+ Channels we have no idea of how potassium channel work until this: patch clamping. -patch clamping is simply to measure current flow across membrane. current refer to movement of charge through space. any time charges move through space , this is current. current can be measured. ions (potassium) moving through aqueous solution constitute an ionic current. the scientist took glass-micropipette (drawn with heat), making an opening at the bottom. if cell surface is clean, it will make a tight seal with clean pipette (adhesive to each other). by chance, you might include a signal ion channel under pipette. then you stuck a wire in back, hold it to amplifier, and measure the current that's flowing through tip of electrode. the only way current can flow through membrane is through open ion channel. this allow analyzation of current across membrane. -most of time there's no current flowing, at periodic interval, current is turn on very rapidly. No it's +10, the - is hashmark. the current is always same amp...
View Full Document

This document was uploaded on 03/09/2014 for the course EXSC 301 at USC.

Ask a homework question - tutors are online