Final answer:
The true statement is A. Ion-channel-coupled receptors can rapidly alter the membrane potential in response to signal binding, as they form an ion channel that allows ions to pass through and change the potential across the membrane.
So, the correct option is A. Ion-channel-coupled receptors can rapidly alter the membrane potential in response to signal binding.
Step-by-step explanation:
The statement that is true among the options provided is: A. Ion-channel-coupled receptors can rapidly alter the membrane potential in response to signal binding.
These receptors, also known as ion channel-linked receptors, bind a ligand and open a channel through the plasma membrane, allowing specific ions to pass through.
This passage of ions can lead to a rapid change in the membrane potential.
B. All enzyme-coupled receptors have an intrinsic catalytic domain on the cytosolic side of the plasma membrane, which is true for many but not all of these receptors.
Statement C indicates that each extracellular signal molecule interacts with a single class of cell-surface receptor, which is not true as a signal molecule may interact with different receptors leading to various cellular responses.
It's also not true that many ion-channel-coupled receptors have an intrinsic catalytic domain on the cytosolic side of the plasma membrane, as they generally do not possess enzymatic activity but instead form an ion channel.
Finally, statement E which states that G-protein-coupled receptors are GTP-binding proteins is incorrect, as it is the G-proteins that bind GTP, not the receptors themselves, which have seven transmembrane domains and interact with G-proteins.
Therefore, the correct option is A. Ion-channel-coupled receptors can rapidly alter the membrane potential in response to signal binding.