Which of the following statements is FALSE?
A: A minor change made to the chemical structure of a drug usually causes little to no change in its
pharmacological activity
B: "Dose" can be defined as the amount of drug that has to be given to produce a concentration at the
receptor that yields the desired level of pharmacologic response.
C: Drug binding to receptors is usually reversible.
D: The intensity of pharmacological response is generally proportional to the number of receptors
occupied by the drug. - Correct Answer A: Aminor change made to the chemical structure of a drug
usually causes little to no change in its pharmacological activity
The most common mechanism by which drugs exert their effects is...
A: by interacting with macromolecules that regulate homeostasis
B: By serving as structural analogs to molecules needed for normal biosynthesis
C: through chemical interactions with small molecules in the body
D: Through colligative properties exerted on body fluids - Correct Answer A: By interacting with
macromolecules that regulate homeostasis
Which statement about drug receptors is TRUE?
1. All receptors have at least two functional domains.
2. Most receptors are regulatory proteins that respond to endogenous chemicals.
3. The two major functions of receptors are ligand binding and message propagation.
A: 1, 2, and 3
B: 1
C: 2
D: 1 and 2
E: 2 and 3 - Correct Answer A: 1, 2, and 3
Which type of drug produces its therapeutic effects by reducing the constituent activity of a receptor?
,A: Inverse agonist
B: Agonist
C: Antagonist
D: Partial agonist-antagonist - Correct Answer A: Inverse agonist
Which type of drug produces its therapeutic effect by inhibiting the effects of an endogenous ligand at a
receptor?
A: Inverse agonist
B: agonist
C: Inverse-antagonist
Partial agonist-antagonist - Correct Answer C: Antagonist
A drug classified as an ____________________________ interacts with a receptor to mimic the effects
of the body's endogenous regulatory substance at that receptor.
A: Agonist
B: Antagonist
C: Inverse agonist - Correct Answer A: Agonist
Which of the following BEST explains why drugs of similar chemical structure acting on the same
receptor can produce different effects at the receptor? That is, why are some drugs agonists, while
other structurally similar drugs antagonists at the same receptor?
A: Receptors exist in two different conformations. Agonists prefer to bind receptors that are in the
active conformation and thus increase receptor activity. Antagonists prefer to bind both active and
inactive conformations equally, reducing receptor availability while not activating receptors that are in
the active conformation.
B: Receptor activation is concentration-dependent and, because of their chemical structures, these
drugs reach the receptor in different concentrations. Drugs reaching the receptor in low concentrations
usually produce antagonist actions; drugs reaching the receptor in high concentrations usually produce
agonist actions.
C: Receptors - Correct Answer A: Receptors exist in two different conformations. Agonists prefer to bind
receptors that are in the active conformation and thus increase receptor activity. Antagonists prefer to
bind both active and inactive conformations equally, reducing receptor availability while not activating
receptors that are in the active conformation.
, Which of the following chemical properties describes the degree of attraction between a drug and its
receptor?
A: Affinity
B: Intrinsic efficacy
C: pKa (acid disassociation constant)
D: KD (equilibrium disassociation constant) - Correct Answer A: Affinity
Which of the following is FALSE concerning competitive antagonists?
A: Competitive antagonists bind to the receptor in an irreversible or nearly irreversible fashion.
B: Sufficiently high concentrations of agonist can surmount the effect of a given concentration of the
antagonist.
C: In the presence of a fixed concentration of agonist, increasing concentrations of a competitive
antagonist progressively inhibits the agonist response.
D: The presence of an antagonist increases the agonist concentration required for a given degree of
therapeutic response. - Correct Answer A: Competitive antagonists bind to the receptor in an
irreversible or nearly irreversible fashion.
Atropine competes with acetylcholine for its receptor, but when it binds to the acetylcholine receptor it
lacks efficacy to produce a response. Atropine is therefore classified as a(n) _____________________
A: Antagonist
B: Agonist
C: Inverse agonist
D: Partial agonist-antagonist - Correct Answer A: Antagonist
Which of the following is NOT TRUE of the quantal dose response?
A: Increasing the dose results in increasing intensity of response until a maximum response is reached.
B: In the quantal response, the subject responds maximally to the administered dose or not at all.
C: A plot of the quantal dose response reveals variability in a population that results from genetic
differences.
A: A minor change made to the chemical structure of a drug usually causes little to no change in its
pharmacological activity
B: "Dose" can be defined as the amount of drug that has to be given to produce a concentration at the
receptor that yields the desired level of pharmacologic response.
C: Drug binding to receptors is usually reversible.
D: The intensity of pharmacological response is generally proportional to the number of receptors
occupied by the drug. - Correct Answer A: Aminor change made to the chemical structure of a drug
usually causes little to no change in its pharmacological activity
The most common mechanism by which drugs exert their effects is...
A: by interacting with macromolecules that regulate homeostasis
B: By serving as structural analogs to molecules needed for normal biosynthesis
C: through chemical interactions with small molecules in the body
D: Through colligative properties exerted on body fluids - Correct Answer A: By interacting with
macromolecules that regulate homeostasis
Which statement about drug receptors is TRUE?
1. All receptors have at least two functional domains.
2. Most receptors are regulatory proteins that respond to endogenous chemicals.
3. The two major functions of receptors are ligand binding and message propagation.
A: 1, 2, and 3
B: 1
C: 2
D: 1 and 2
E: 2 and 3 - Correct Answer A: 1, 2, and 3
Which type of drug produces its therapeutic effects by reducing the constituent activity of a receptor?
,A: Inverse agonist
B: Agonist
C: Antagonist
D: Partial agonist-antagonist - Correct Answer A: Inverse agonist
Which type of drug produces its therapeutic effect by inhibiting the effects of an endogenous ligand at a
receptor?
A: Inverse agonist
B: agonist
C: Inverse-antagonist
Partial agonist-antagonist - Correct Answer C: Antagonist
A drug classified as an ____________________________ interacts with a receptor to mimic the effects
of the body's endogenous regulatory substance at that receptor.
A: Agonist
B: Antagonist
C: Inverse agonist - Correct Answer A: Agonist
Which of the following BEST explains why drugs of similar chemical structure acting on the same
receptor can produce different effects at the receptor? That is, why are some drugs agonists, while
other structurally similar drugs antagonists at the same receptor?
A: Receptors exist in two different conformations. Agonists prefer to bind receptors that are in the
active conformation and thus increase receptor activity. Antagonists prefer to bind both active and
inactive conformations equally, reducing receptor availability while not activating receptors that are in
the active conformation.
B: Receptor activation is concentration-dependent and, because of their chemical structures, these
drugs reach the receptor in different concentrations. Drugs reaching the receptor in low concentrations
usually produce antagonist actions; drugs reaching the receptor in high concentrations usually produce
agonist actions.
C: Receptors - Correct Answer A: Receptors exist in two different conformations. Agonists prefer to bind
receptors that are in the active conformation and thus increase receptor activity. Antagonists prefer to
bind both active and inactive conformations equally, reducing receptor availability while not activating
receptors that are in the active conformation.
, Which of the following chemical properties describes the degree of attraction between a drug and its
receptor?
A: Affinity
B: Intrinsic efficacy
C: pKa (acid disassociation constant)
D: KD (equilibrium disassociation constant) - Correct Answer A: Affinity
Which of the following is FALSE concerning competitive antagonists?
A: Competitive antagonists bind to the receptor in an irreversible or nearly irreversible fashion.
B: Sufficiently high concentrations of agonist can surmount the effect of a given concentration of the
antagonist.
C: In the presence of a fixed concentration of agonist, increasing concentrations of a competitive
antagonist progressively inhibits the agonist response.
D: The presence of an antagonist increases the agonist concentration required for a given degree of
therapeutic response. - Correct Answer A: Competitive antagonists bind to the receptor in an
irreversible or nearly irreversible fashion.
Atropine competes with acetylcholine for its receptor, but when it binds to the acetylcholine receptor it
lacks efficacy to produce a response. Atropine is therefore classified as a(n) _____________________
A: Antagonist
B: Agonist
C: Inverse agonist
D: Partial agonist-antagonist - Correct Answer A: Antagonist
Which of the following is NOT TRUE of the quantal dose response?
A: Increasing the dose results in increasing intensity of response until a maximum response is reached.
B: In the quantal response, the subject responds maximally to the administered dose or not at all.
C: A plot of the quantal dose response reveals variability in a population that results from genetic
differences.
