Answer
Gates, unlike other channel proteins, open and close depending on the situation, thus getting to decide which solute molecules can pass through the membrane. Three types of stimuli cause the gates to open and close. These are: chemical messengers, changes in voltage, and physical stress on the cell.
Work Step by Step
Channels are passages or tunnels that allow for certain water loving molecules to pass through the cell membrane. Unlike gates, they are always opened, and are usually surrounded by several proteins. There are three types of channels that respond to different stimuli that in turn open a specific gate. Ligand-gated channels respond to chemical messengers such as neurotransmitters, and allow the entrance of molecules including potassium, sodium, calcium, or chloride. Voltage-gated channels respond to changes in both electrical potential, and ion concentration. Mechanically gated channels respond to physical stress put on the cell, such as stretching or pressure. These channels are specifically helpful in the process of muscle contraction.
