Resting Potential

Question 1

What is the charge in a resting neurone ?

Answer 1

The inside of the axon membrane is more negative than the outside

Question 2

What is a resting potential?

Answer 2

When the axon isn’t conducting an impulse and the unequal distribution of ions maintain the resting potential.

Question 3

How is a resting potential maintained?

Answer 3

The permeabiity of the membrane to potassium and sodium ions.
The action (active transport) of the sodium/potassium pump.

Question 4

Explain how membrane permeability and sodium potassium pumps create a resting potential.

Answer 4

• The membrane is more permeable to K as most of the potassium gates of ion channels are open. More K are diffusing out than Na are diffusing in so there are more ions outside the axon.
• The resting potential is maintained by the sodium-potassium pump which actively transports (hydrolysis of ATP) ions against their concentration gradient, maintaining the electrochemical gradient.