Which type of transmembrane protein is correctly matched with its function?
a. transporter - identifies what type of cell contains the protein
b. cell-to-cell adhesion - allows specific molecules to pass through the membrane
c. cell surface receptor - changes shape and sends signals into a cell when it binds to an extracellular ligand
d. cell surface identity marker - catalyzes reactions at the surface of the membrane it is in
e. enzyme - attaches to the cytoskeleton to maintain the shape of the cell
