Which of the Following Statements Is True

Multiple Choice

Which of the following statements is true?

A) G proteins contain only one important binding site.
B) When a G protein binds to an activated receptor protein, ADP is exchanged for ATP.
C) G protein receptors are single proteins that have seven distinct regions that pass through the phospholipid bilayer of the cell membrane.
D) G proteins can only activate effector proteins; they cannot inhibit them.
E) None of the above