If the pinsulin receptor, a, example of an integral membrane protein, is cotranslationally inserted into the er membrane with the n-terminus on the cytosolic side of the membrane and the c-terminus in the lumen of the er, which side of the protein would you expect to bind to the ligand, pinsulin, when the protein is found on the cell surface?
(a) n-terminal end of the protein will bind pinsulin
(b) neither will bind to a ligand because both ends of the protein will be extracellular and will compete with each other
(c) c-terminal end of the protein will bind pinsulin
(d) neither will bind to a ligand because both ends of the protein will be cytoplasmic