Question

When a voltage gated na channel opens,_______

A. many different ions leak through the channel depending upon their gradient
B. sodium ions move through the channel depending upon their gradient
C. a molecule or neurotransmitter has attached to its receptor
D. there has been a change in the membrane potential of the cell

Answer 1

When a voltage-gated Na+ channel opens, sodium ions move through the channel due to the concentration gradient, causing depolarization of the cell membrane.

Step-by-step explanation:

When a voltage-gated Na+ channel opens, sodium ions move through the channel depending upon their gradient. This process is a critical component of the action potential in neurons. As sodium enters the cell, it causes the membrane potential to become less negative, a process known as depolarization.

This electrical change is possible because the concentration of sodium is higher outside of the cell than inside, creating a strong concentration gradient. Additionally, the negatively charged proteins inside the cell attract the positively charged sodium ions, influencing their movement into the cell. Voltage-gated sodium channels are distinct from other types such as ligand-gated or mechanically gated channels, which open in response to different stimuli such as neurotransmitter binding or physical pressure, respectively.