Part a to what does the term "ligand" refer in cell biology? view available hint(s) to what does the term "ligand" refer in cell biology? the change in shape that occurs when a signaling molecule binds to its receptor the target cell of a signal molecule the bond that forms between a signaling molecule and its receptor any small molecule that can bind in a specific manner to a larger one a molecule that can occupy a receptor site while not activating the receptor