Achannel that opens in response to the binding of a specific molecule, which is usually not the solute that passes through the channel is called a

The answer is ligand gated channels.

Ligand gated channels are also called as ionotropic receptors that open in response to the binding of specific ion, which is generally not solute. These are made up of particular set of transmembrane proteins that open and close to allow the movement of ions like K+, Na+ that passes through the plasma membrane in response to binding of the chemical messenger.