AP BIOLOGY

Detailed explanation-1: -A Ligand-gated Ion Channel: Ligand-gated ion channels (LGICs) are one type of ionotropic receptor or channel-linked receptor. They are a group of transmembrane ion channels that open or close in response to the binding of a chemical messenger (ligand), such as a neurotransmitter.

Detailed explanation-2: -Ligand-gated ion channels bind neurotransmitters and open in response to ligand binding. These channels control synaptic transmission between two neurons or between a neuron and a muscle.

Detailed explanation-3: -Ligand-Gated Ion Channels Typically, each subunit contains 4 hydrophobic transmembrane domains linked by hydrophilic groups. Activation of these channels leads to a rapid (msec) response, allowing ions to flow down their electrochemical gradients.

Detailed explanation-4: -If these receptors are ligand-gated ion channels, a resulting conformational change opens the ion channels, which leads to a flow of ions across the cell membrane. This, in turn, results in either a depolarization, for an excitatory receptor response, or a hyperpolarization, for an inhibitory response.