Question

The BEST understood gated channel is:

a. the channel in the inner ear that responds to sound
b. an aquaporin
c. voltage-gated potassium ion channels
d. the ligand-gated nicotinic acetylcholine receptor
e. channels in the integument of the model organism C. elegans

Answer 1

The best understood gated channel is the ligand-gated nicotinic acetylcholine receptor, which opens in response to a neurotransmitter binding, allowing ions to pass and alter the membrane charge.

Step-by-step explanation:

The best understood gated channel is d. the ligand-gated nicotinic acetylcholine receptor. A ligand-gated channel is a type of ionotropic receptor that opens when a ligand, such as a neurotransmitter, binds to its extracellular region. In the case of the nicotinic acetylcholine receptor, the binding of acetylcholine causes the pore of the channel to open, allowing selective ions (cations of sodium, calcium, and potassium) to flow through and change the charge of the membrane (Figure 12.18).

This process is crucial for the transmission of signals in the nervous system. Unlike voltage-gated channels that respond to changes in electrical properties or mechanically-gated channels that respond to physical deformation, ligand-gated channels are directly triggered by chemical signals, making them extremely important for intercellular communication.