Cells grown in the laboratory are mixed with a dye molecule that is unable to pass through the plasma membrane. If a ligand is added to the cells, observations show that the dye enters the cells. What type of receptor did the ligand bind to on the cell surface?

The ligand bind with an ion channel receptor present on the surface of the cell. After combining the ion channel receptor opened a pore in the membrane that permitted the ionic dye to move within the cell. These ion channel receptors are generally the multimeric proteins situated in the plasma membrane and possess the tendency to close and open in response to mechanical or chemical signals.