Compare and contrast hyperpolarization and depolarization Di

Compare and contrast hyperpolarization and depolarization. Discuss what ions may be involved and the direction of flow across the membrane.

Solution

Hyperpolarization

depolarization

Membrane potential becomes more negative as a result of flow of positive ions out of the cell

Opening of K+ channels and after a phase of depolarization brings the membrane potential to resting state. Since K+ channels are open for longer time there is further efflux of K+ ions causing membrane potential to go further negative than resting membrane potential.

-75 mV going to -90 mV

Hyperpolarization doesn’t result in action potential.

depolarization happens when the membrane potential becomes less negative (more positive).

This is due to influx of Na+ ions into the cell due to Na+ channel opening.

Once a threshold of depolarization is reached the cell fires action potential.