Action Potential Phases Ion Channels
Depolarization phase Voltage-gated sodium channels
Repolarization phase Voltage-gated potassium channels
Hyperpolarization phase Chemically-gated potassium channels
Here's a more detailed explanation of each phase:
Depolarization phase:
The depolarization phase is the initial rapid increase in membrane potential. This is caused by the opening of voltage-gated sodium channels.
These channels are normally closed at the resting membrane potential, but when the membrane potential reaches a certain threshold, they open and allow sodium ions to rush into the cell. This influx of positively charged ions causes the membrane potential to rise sharply.
Repolarization phase:
The repolarization phase is the rapid decrease in membrane potential that follows the depolarization phase. This is caused by the opening of voltage-gated potassium channels.
These channels are also normally closed at the resting membrane potential, but they open more slowly than voltage-gated sodium channels. When they open, they allow potassium ions to exit the cell. This efflux of positively charged ions causes the membrane potential to fall back towards its resting value.
Hyperpolarization phase:
The hyperpolarization phase is a brief period of time during which the membrane potential is more negative than the resting membrane potential. This is caused by the opening of chemically-gated potassium channels.
Question
For each phase of an action potential, indicate the ion channel most responsible for the membrane potential change that occurs during the phase.
Action Potential Phases
Ion Channels
Depolarization phase
Repolarization phase
Hyperpolarization phase
Voltage-gated potassium channels
Voltage-gated sodium channels
Chemically-gated potassium channels
Chemically-gated sodium channels ,complete the table .