Which Statement About Signal Transduction in Cells Can Be Used

Multiple Choice

Which statement about signal transduction in cells can be used to explain how specificity is achieved in a signal transduction pathway?

A) Receptors that bind chemical signals are either membrane receptors located on the cell surface or internal receptors present in the interior of a cell.
B) The sensitivity of a cell to a chemical signal is determined in part by the affinity of the cell's receptors for the signal molecule.
C) The binding of a small molecule to a site on a receptor is reversible, and equilibrium is reached when the rate of binding equals the rate of dissociation.
D) Agonists are chemicals that bind to a receptor and stimulate a signal transduction pathway just as the natural ligand does.
E) A receptor protein changes its conformation only when its binding site is occupied by a small molecule with a shape complementary to the site.