Human Phys 2.1

Question 1

Diffusion potential

Answer 1

Potential difference generated across a membrane when an ion diffuses down its concentration gradient

Question 2

What is the only way diffusion potentials can be generated?

Answer 2

If the membrane is permeable to the ion

Question 3

What does the magnitude of the diffusion potential depend on?

Answer 3

Size of concentration gradient

Question 4

Equilibrium potential

Answer 4

Diffusion potential that exactly balances or opposes the tendency for diffusion down the concentration gradient

Question 5

When did electrochemical equilibrium occur?

Answer 5

When the chemical and electrical driving forces acting on an ion are equal and opposite

Question 6

When do membrane potentials arise?

Answer 6

When there is a difference in electrical charge between both sides of a membrane

Question 7

What can charge differences result from?

Answer 7

Passive ion diffusion (open Na+ channel)

Electrogenic pumping (Na+K+ pump)

Question 8

Why does K+ play an essential role in balancing Na+ in ICF?

Answer 8

Due to K+ leak channels (K+ can move while membrane is at rest)