MCP

Question 1

Simplified Nernst Equation for Potassium?

Answer 1

Ek= 60*log(Koutside/Kinside)

Question 2

Conductance Eqn?

Answer 2

Vm=(EkGk)+(EnaGna)/(Gk+Gna)

Question 3

Time Constant Equation?

Answer 3

T=Rmembrane*Cmembrane

Question 4

Time Constant Purpose?

Answer 4

Finds the amount of time to charge and discharge membrane capacitance

Question 5

Space Constant Equation

Answer 5

Lamba=sqrt(Rmembrane)/sqrt(Rinternal)

Question 6

Space Constant Purpose

Answer 6

Finds how far an action potential can travel before reaching 37% of its initial strength

Question 7

Functions of:
TTX:
STX:
TEA:

Answer 7

TTX&STX block Na channels so you can measure potassium’s effect on current alone.

TEA blocks K channels, so you can measure sodium’s effect on current alone.

Question 8

6 Steps for action potential

Answer 8

1. Electrical threshold reached in which GNa>GK
2. Na+ Rushes in the cell and depolarizes
3. Overshoot (Max(+)) is reached
4. Na channel become closed-inactive
5. K+ channels open (slower than Na) and repolarize the cell
6. Slight undershoot/hyperpolarization caused by K+ staying open for a long time

Question 9

Plasma Membrane Flux & Fick’s Law

Answer 9

Mem Flux: Jx=Px*(Xo-Xi)

Fick’s: DiA(C1-C2)/X

Question 10

Capacitance

Answer 10

q/V, where V=(V*E_nernst)