Establishing membrane potential

Question 1

What is potential energy? What mathematical eqation is it defined by?

Answer 1

The ability to do work

Slope

Question 2

What pump uses ATP to use energy to restore membrane potential?

Answer 2

3Na+/2K+ ATPase

Question 3

Do excitable cells use both concentration and electrical gradients for energy?

Answer 3

Yes

Question 4

What 2 factors will increase conductance?

Answer 4

Add salt

Increase permeability

Question 5

What are electro-chemical potentials?

Answer 5

A chemical that has a concentration & electrical gradient

Question 6

When does electrical gradient cease the net flux of ions down a concentration gradient?

Answer 6

K+ diffuses down concentration gradient through K+ channel until the opposing side becomes sufficiently electro-positive

Question 7

Which has a larger magnitude, concentration or electrical gradient?

Answer 7

They are equal

Question 8

Is the Fick gradient electrical or chemical? Does it flow to the right or left?

Answer 8

Chemical

Flows left to right

Question 9

Is the Ohm equation electrical or chemical? Does it flow to the right or left?

Answer 9

Electrical

Flows right to left

Question 10

IS the reference electrode intracellular or extracellular? Sensing electrode?

Answer 10

Extracellular

Intracellular

Question 11

What are the 3 things the Nernst equation defines?

Answer 11

Equilibrium conditions
The direction an ion will flow
Membrane potential (if membrane is permeant to 1 ion)

Question 12

What temperature does the Nernst potential work at?

Answer 12

37 degrees C

Question 13

What is the typical resting membrane potential for a membrane perfectly permeable to K+?

Answer 13

-90mV

Question 14

What are the minimum requirements to establish resting membrane potential?

Answer 14

Gradients
Charge carrier
Conductive pathway
power source