Fundamentals Of Neuronal Function Ion Channels

Question 1

How is potential energy provided?

Answer 1

Differences in ion concentrations across the nerve cell membrane

Question 2

What are used to measure potential difference?

Answer 2

Intracellular microelectrodes

Question 3

What is the symbol for resting membrane potential and do all cells have it?

Answer 3

Vm and yes

Question 4

What are the 6 steps the Na/k ATPase works?

Answer 4

1) binding of Na+ stimulates phosphorylation by ATP
2) phosphorylation causes conformational change
3) Na+ expelled and K+ binds
4) k+ binding releases phosphorylate group
5) restores OG conformation
6) K+ released and Na+ sites receptive again

Question 5

What is the resting membrane potential due to?

Answer 5

Permeability of K+

Question 6

How is equilibrium of potassium established?

Answer 6

Conc grad tends to drive k+ out of the cell but -ve charge inside attracts k+ back in

Question 7

Define the equilibrium potential

Answer 7

Voltage at which the electrical force experienced by an ion is equal and opposite to the chemical force produced by the conc grad

Question 8

State the Nernst equation

Answer 8

61.5log [K+o]/k+i]

Question 9

What do excitable cells use to do work?

Answer 9

Potential energy