Which of the following hormones requires a cell surface receptor for its action? (a) Adrenaline (b) Progesterone (c) Growth factors (d) All of the above
Cell-surface receptors come in three main types: ion channel receptors, GPCRs, and enzyme-linked receptors. Ion channel receptors: When a ligand binds an ion channel receptor, a channel through the plasma membrane opens that allows specific ions to pass through.
