Question

Match the best term (hyperpolarize, depolarize, repolarize) to the following events. The cell in question has a resting membrane potential of −70 mV.

membrane potential changes from −70 mV to −50 mV

membrane potential changes from −70 mV to −90 mV

membrane potential changes from +20 mV to −60 mV

membrane potential changes from −80 mV to −70 mV

Answer 1

Matching the correct terms, a membrane potential change from -70 mV to -50 mV is depolarization, from -70 mV to -90 mV is hyperpolarization, from +20 mV to -60 mV is repolarization, and from -80 mV to -70 mV is also repolarization as it approaches resting state.

Step-by-step explanation:

The cell's resting membrane potential is typically around -70 mV. Different movements of ions across the cell membrane can cause this potential to change, characterizing different stages of an action potential:

• If the membrane potential changes from −70 mV to −50 mV, this is called depolarization, as the cell becomes less negative (or more positive) relative to the outside.
• When the membrane potential changes from −70 mV to −90 mV, the term hyperpolarization is used because the cell becomes more negative than at rest.
• The change from +20 mV back to −60 mV represents repolarization, as the cell returns towards the resting membrane potential but is not yet at the resting state.
• Lastly, changing from −80 mV back to −70 mV is an adjustment towards the resting potential, but since it's from a more negative value it can also be considered repolarization, as the potential moves towards the normal resting state.