Problem 1
The description of molecular events initiated with the ligand binding and ending with a pharmacologic effect is called (A) receptor down-regulation. (B) signal transduction pathway. (C) ligand-receptor binding. (D) law of mass action. (E) intrinsic activity or efficacy.
Problem 2
G protein-coupled receptors that activate an inhibitory \(\mathrm{G}_\alpha\) subunit alter the activity of adenylate cyclase to (A) increase the coupling of receptor to \(\mathrm{G}\) protein. (B) block the ligand from binding. (C) initiate the conversion of GTP to GDP. (D) generate intracellular inositol triphosphate. (E) decrease the production of cAMP.
Problem 3
The law of mass action explains the relationship between (A) the dose of drug and physiologic response. (B) the concentration of drug and the association/dissociation of drug- receptor complex. (C) receptors and the rate of signal transduction. (D) an enzyme and ligands that inhibit the enzyme. (E) graded and quantal dose-response curves.
Problem 4
In a log dose-response plot, drug efficacy is determined by the maximal height of the measured response on the effect axis, whereas drug potency is determined by (A) the number of animals exhibiting an all-or-none response. (B) the signal transduction pathway. (C) the formula, including the affinity of the drug and the number of drug receptors. (D) the position of the curve along the log-dose axis. (E) the steepness of the dose-response curve.
Problem 5
A partial agonist is best described as an agent that (A) has low potency but high efficacy. (B) has affinity but lacks efficacy. (C) interacts with more than one receptor type. (D) cannot produce the full effect, even at high doses. (E) blocks the effect of the antagonist.
