Which Statement About Membrane Receptors in a Signal Transduction Pathway

Multiple Choice

Which statement about membrane receptors in a signal transduction pathway is true?

A) They are embedded in the cell membrane but do not span its width.
B) Ligands bind to the extracellular binding domain and then enter the cell.
C) Ligands bind to the extracellular binding domain and do not enter the cell.
D) Ligands enter the cell and bind to the cytoplasmic side of the receptor.
E) Ligands bind irreversibly to the membrane receptor.