Final answer:
Hydrophilic ligands use cell-surface receptors such as extracellular receptors, GPCRs, ligand-gated ion channels, and enzyme-linked receptors to transmit signals into the cell. The correct options are 2 3 5.
Step-by-step explanation:
Hydrophilic ligands cannot cross the cellular membrane and instead bind to cell-surface receptors. These receptors, such as extracellular receptors (cell surface receptors), G-protein-coupled receptors (GPCRs), ligand-gated ion channels, and enzyme-linked receptors, transmit signals from outside the cell into a response within the cell.
Cell-surface receptors span the plasma membrane and convert external signals into internal ones, allowing water-soluble hydrophilic ligands to trigger cellular responses without entering the cell. The correct options are 2 3 5.