Peptide Hormones and Epinephrine

Question

Peptide hormones and epinephrine
A)readily diffuse through the plasma membrane and the nuclear membrane.
B)readily diffuse through the plasma membrane but not the nuclear membrane.
C)are too large to pass across the plasma membrane.
D)are steroid hormones.
E)are second messengers.

Accepted Answer

Peptide hormones and epinephrine are too large and polar to pass directly through the lipid bilayer of the plasma membrane, requiring specific receptors on the cell surface to mediate their effects.