SM35

Question 1

Properties that define receptors

Answer 1

biological specificity; chemical specificity; selective antagonism; cloning, sequencing and expression of specific receptor subtypes

Question 2

The _______ _______ in an equation that describes the fraction of drug bound as a function of drug concentration

Answer 2

rectangular hyperbola

Question 3

________ _______ ____ is the concentration of the drug that produces 50% of maximcal effect

Answer 3

Effective Concentration 50%

Question 4

While noncompetitive antagonists ______ the maximal response and ______ the agonist potency / EC50, competitive antagonists ____ the maximal response and ____ the EC50

Answer 4

Noncompetitive antagonists decrease maximal response and do not alter potency; Competitive antagonists do not alter maximal response and increase the EC50.

Question 5

______ inhibitors decrease both the EC50 and maximal response

Answer 5

Uncompetitive

Question 6

_____ inhibitors bind only to the orthosteric site

Answer 6

competitive

Question 7

At high concentrations, _______ ______ can act as competitive inhibitors to full agonists

Answer 7

partial agonists

Question 8

Receptors involved in intricate signal transduction cascades are often called ______ receptors because of amplification involved in signaling

Answer 8

spare receptors; a full agonist can product maximal response with only a small portion of the total receptor population occupied –> unoccupied (spare) receptors

Question 9

In spare receptors, what can produce a shift of the log dose response curve to the right without a change in maximum?

Answer 9

low doses of ANY antagonist

Question 10

In contrast to true competitive inhibition, if the concentration of a non-competitive antagonist is increased, eventually the maximal response to the full agonist is ______

Answer 10

decreased

Question 11

Graphically, cooperativity is observed by an __-shaped beginning of the dose response curve on arithmetic coordinated

Answer 11

S

Question 12

____________ is known as the mathematical modification of the rectangular hyperbola used to describe cooperativity. What is that mathematical modification

Answer 12

The hill equation; raising the concentration term in the rectangular hyperbola to a power

Question 13

Mechanisms of cooperativity

Answer 13

binding of one molecule influences binding of another molecule; more than one molecule bound is needed to activate a receptor but binding is independent; the relationship between binding and response is cooperative; multiple receptors existing as subunits

Question 14

Different types of response curves and why they are different

Answer 14

Graded dose response curve; quantal dose response curve; median effective dose and median lethal dose

Question 15

What does it mean for a receptor to be constitutively active

Answer 15

Receptors are active in producing a biological response in the absence of agonist

Question 16

Constitutive activation is or is not a general property of receptors?

Answer 16

IS NOT. This is a property that occurs when the concentration of receptors becomes very high (artificial expression systems and tumors)

Question 17

________ agonists bind to the orthosteric site but do NOT elicit a maximal response

Answer 17

partial

Question 18

Define the therapeutic index

Answer 18

Ratio of toxic ED50 to therapeutic ED50. A higher T.I. indicates a safer drug bc it indicates a wider range of dosage that can be administered before being limited by toxicity

Question 19

How can you distinguish types of antagonists in spare receptor system?

Answer 19

Keep increasing the antagonist concentration! For noncompetitive and uncompetitive, eventually, the maximal response will be decreased. If the maximal response remains the same, the antagonist is competitiv