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.

Question

Quizplus · Accepted Answer

Membrane receptors in a signal transduction pathway are typically transmembrane proteins that span the width of the cell membrane. Ligands bind to the extracellular binding domain of the receptor, but they do not enter the cell. Instead, the binding of the ligand to the receptor triggers a conformational change in the receptor that initiates the signaling cascade inside the cell. Therefore, option C is the correct statement.

Which Statement About Membrane Receptors in a Signal Transduction Pathway