lectures 10 & 11

Question 1

Binding of an ______ results in an induced fit that activates the receptor.

Answer 1

agonist

Question 2

Binding of an ______ results in a different induced fit that does not activate the receptor.

Answer 2

antagonist

Question 3

______ is the dose of a drug required to produce a particular effect of given intensity. It is a comparison based on doses that produce the same effect (usually ED50)

Answer 3

potency

Question 4

______ is the biological response resulting from the drug-receptor interaction

Answer 4

efficacy

Question 5

A strong agonist has _____ affinity and _____ efficacy.

Answer 5

high
high

Question 6

Efficacy is (more/less) important than potency as a drug property.

Answer 6

more

Question 7

Maximal efficacy is often limited by _______.

Answer 7

toxicity

Question 8

A _______ produces a reduced response even at full receptor occupancy. It cannot produce the same maximal effect as a full agonist, regardless of the concentration used.

Answer 8

partial agonist

Question 9

________ produce the opposite response of an agonist. They require constitutive activity and stabilize the inactive form of the receptor.

Answer 9

Inverse agonists

Question 10

__________ is a drug-receptor interaction that interferes with or prevents the development of a drug response by an agonist.

Answer 10

Receptor antagonism

Question 11

What are the three major types of receptor antagonists?

Answer 11

competitive
non-competitive
irreversible

Question 12

In _______ antagonism, the antagonist binds to the same site on the receptor as the agonist.

Answer 12

competitive

Question 13

Can competitive antagonism be reversed? If so, how?

Answer 13

yes, by increasing the dose of the agonist

Question 14

The log dose-response curve for an agonist in the presence of a competitive antagonist will be shifted to the _____, indicating a reduction in ______ of the agonist. The shape of the curve and the maximal response are not altered.

Answer 14

right
potency

Question 15

A competitive antagonist has ______ but lacks ______.

Answer 15

affinity
efficacy

Question 16

In ________ antagonism, the antagonist produces its effect at a site of the receptor other than the site used by the agonist.

Answer 16

non-competitive

Question 17

Can non-competitive antagonism be reversed?

Answer 17

no

Question 18

Increasing the antagonist concentrations _______ the KD and _____ the Emax of the agonist.

Answer 18

increases
decreases

Question 19

In the presence of a non-competitive antagonist, the dose-response curve is shifted to the ______.

Answer 19

right

Question 20

As the dose of non-competitive agonist is increased, the maximal response obtained is _____.

Answer 20

decreased

Question 21

In ______ antagonism, the initial dose-response curve may be shifted to the right, resembling competitive inhibition.

Answer 21

irreversible

Question 22

In irreversible antagonism, as the antagonist concentration is _____ and the spare receptors are occupied, the maximal response is ______, resembling non-competitive inhibition.

Answer 22

increased
decreased

Question 23

An irreversible antagonist will usually bind to ________, but will not be readily displaced.

Answer 23

the same site as the agonist

Question 24

Irreversible inhibition is generally caused by _______ reaction between antagonist and receptor.

Answer 24

covalent

Question 25

_________ are present when the maximal response can be elicited by an agonist at a concentration that does not result in 100% occupancy of available receptors.

Answer 25

spare receptors

Question 26

Which of the following is not true regarding spare receptors? A. It is system/tissue dependent B. Allow a noncompetitive antagonist to look like a competitive antagonist C. Spare receptors are independent of effector molecules D. May differ between signaling pathways with the same receptor

Answer 26

C dependent of effector numbers

Question 27

Which of the following is not true regarding antagonists? A. Irreversible and allosteric antagonists have similar effects on the dose response curves of agonists B. In the absence of spare receptors, a noncompetitive antagonist increases the Emax C. Irreversible antagonists typically bind the orthosteric site D. Antagonist affinity can be estimated using a Schild plot

Answer 27

B we have not talked about anything that can increase Emax

Question 28

___________ antagonism is when two drugs influence a physiological system but in opposite directions. Each drug is unhindered in the ability to elicit its own characteristic response. (ex: the effect of histamine on blood pressure can be offset by epinepherine)

Answer 28

functional/physiological

Question 29

_________ antagonism is when a chemical reaction occurs between an agonist and an antagonist to form an inactive product.

Answer 29

chemical

Question 30

In chemical antagonism, the agonist is ______ in direct proportion to the extent of the chemical reaction with the antagonist. (ex: calcium-containing antacids and tetracycline antibiotics)

Answer 30

inactivated

Question 31

________ bind at sites unique from the agonist or antagonist. They can be PAMs or NAMs.

Answer 31

allosteric modulators

Question 32

Allosteric ligands have increased _______ for receptors that have very similar orthosteric binding sites, with increased safety due to ceiling effect and provide more physiological/temporal signaling.

Answer 32

specificity

Question 33

Which of the following statements about allosteric ligands is false? A. Allosteric modulators bind at sites unique from the agonist (or antagonist). B. Negative allosteric modulators (NAMs) are noncompetitive. C. Positive allosteric modulators are safer than orthosteric modulators. D. There are no FDA-approved allosteric modulators. E. Allosteric modulators would also regulate inverse agonists.

Answer 33

D PAMs of dopamine receptors for early Parkinson's disease or adjunctive therapy with L-DOPA or D2 agonists