Homework_02_solution

Homework_02_solution - BME 402 Ion channels Homework 2 Due...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
BME 402 Homework 2 Due 11am, 1/31/06 Ion channels Ion channels are among the most important molecules in living organisms, and certainly in the brain. The are involved in all neural signaling, including the establishment of the resting membrane potential, and all voltage signaling on top of that. Many drugs (and toxins) act on ion channels, often mimicking the action of endogenous neurochemicals. Know their range of atomic weights, and the basic physical structure (i.e. be able to draw an ion channel in schematic form). Know a few examples of one or more drugs that act on ion channels, and one or more neurotoxins, and be able to state how the drug or toxin affects the channel and how that translates into a change in the behavior of the animal. Understand basics of ion flow through a channel: is it active or passive, what are basic mechanisms of selectivity, how many ions can flow per second. Be able to draw a typical current trace of an ion channel opening and closing with time. Be able to list 4 types of gating of ion channels. Membrane potential Be able to explain how the resting potential comes about as a result of the ionic concentration gradients and selective permeability that exist across the bilipid membrane. Specifically, you should memorize (1) the Nernst equation including the constants at 37degC, (2) the GHK equation for the membrane potential, and (3) the simpler weighted- average-of-batteries equation for the steady state membrane potential. For the four main current-carrying ions in the brain (know their names), know which way the concentration gradients point (higher inside or outside), and whether the ion contributes to a more positive or more negative membrane potential. Understand the reason for and effect of the Na+/K+ pump, and know what it means for an ion to be passively distributed. Know Ohm's law, and the law relating charge to voltage on a capacitor. Know how to calculate input resistance and capacitance given a value of R m of C m and the cell size. Homework question:
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This homework help was uploaded on 10/23/2007 for the course BME 402 taught by Professor Mel during the Spring '06 term at USC.

Page1 / 6

Homework_02_solution - BME 402 Ion channels Homework 2 Due...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online