Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pharmacology > Lecture 3: Pharmacodynamics Part 2 > Flashcards

Lecture 3: Pharmacodynamics Part 2 Flashcards

1
Q

t/f all receptors exhibit similar basic principles wrt their interactions with drugs

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

there are __ primary classes of receptors

A

4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are the 4 primary classes of receptors?

A
  1. intracellular receptors
  2. enzyme-linked receptors
  3. ligand gated ion channels
  4. GPCRs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

the intracellular class of receptors is sometimes further subdivided for receptors that remain in the __. These are called __

A

nucleus; intranuclear receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is unique about intracellular class receptors?

A

the ligands acting on them must enter the cell in order to have their effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

enzyme-linked receptors can be divided into what 2 categories?

A
  1. receptors that have enzymatic site as part of the receptor itself
  2. receptors that are associated with intracellular enzymes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

in enzyme-linked receptors, activation of receptor causes __

A

increased activity of an enzyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are ligand gated ion channels?

A

membrane channels that allow passage of ions based on binding ion ligand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are G protein coupled receptors?

A

large proteins characterized by 7 transmembrane spanning domains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

in a GPCR, the intracellular domain associates with a __, which when activated will initiate a series of __ to cases a cellular response

A

G protein complex; cellular events

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

most drugs that bind to intracellular receptors are __ soluble. why is this?

A

fat. to cross the lipid membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

when activated, intracellular receptors do what 3 things?

A

. Interact with gene response elements on DNA and modulate gene transcription, resulting in changes in protein synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the time frame of intracellular receptor drugs to have aparent effects?

A

several hours to days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

why does it take so long for intarcellaulr receptor drugs to take effect?

A

processes of receptor stimulation to protein synthesis takes a significant amount of time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

explain the structure of enzyme linked receptors

A

2 transmembrane spanning units with ligand binding sites the extracellular domains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what happens to the 2 subunits of an enzyme linked receptor when a ligand binds?

A

the 2 subunits associate together to initiate enzymatic activity within the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

give an example of an enzyme linked receptor that associates with intracellular tyrosine kinase enzymes

A

interleukin 2 (iL 2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

the epidermal growth factor is an example of a ___ type receptor, which contains ___ as part of the intracellular parts of the receptor itself

A

tyrosine kinase; enzymatic domains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

the associated / “built in” tyrosine kinase domains initiate ___ when receptor is activated

A

intracellular signalling cascade

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

when 2 receptor subunits associate, they become __ in relation to each other and this allows them to _____, which is called ___

A

closer; phosphorylate each other; autophosphorylation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is the role of autophosphorylation of 2 receptor subunits?

A

activates enzymatic activity and initiates the downstream signalling response in the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is it called when two receptor subunits associate?

A

dimerization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

give an example of ligand gated ion channels

A

nicotinic acetylcholine receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

ligand gated ion channels contain a ___ that when opened allows the flow of ions across the membrane

A

transmembrane pore

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

where can ligand gated ion channels be found in the body?

A

in neurons and muscle cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

binding of a ligand to a ligand gated ion channel causes what to happen to the receptor?

A

changes conformation, resulting in the opening of the channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

opening of ligand gated ion channel results in ___

A

action potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

the time from the ligand binding to the gated ion channel receptor to when there is a physiologic response (such as muscle contraction) is very __

A

fast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

give an example of GPCR

A

beta adrenergic receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

___ is the largest class of drug-targeted receptors

A

GPCR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

it is estimated that approximately ___% of drugs interact with GPCR

A

50

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

A GPCR has __ transmembrane domains with an ___ formed within them

A

7; agonist binding site

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

the intracellular domain of a GPCR interacts with the __

A

G protein complex

34
Q

when an agonist binds to the GPCR pocket, there is a conformational change in the large ___ protein, which facilitates now the exchange of ___ for ___

A

G; GDP for ATP

35
Q

what happens to the high-energy G protein complex and the G protein subunits after exchanging GDP for GTP?

A

the high energy G protein complex dissociates from the receptor and the subunits (alpha and beta) separate and initiate intracellular signalling cascades

36
Q

when epinephrine activates the beta-adrenergic receptors in the heart, what g-protein is activated?

A

G alpha s (stimulatory_

37
Q

when a GPCR is coupled to a Gs protein, the activated __ subunit dissociates and increases the __ activity of ___

A

alpha; enzymatic; adenyl cyclase

38
Q

adenyl cyclase catalyses the reaction that converts __ to __

A

ATP to cAMP

39
Q

what is cAMP and its role?

A

second messenger within cells that activates other proteins

40
Q

one of the primary effector molecules activated by the Gs signalling pathway is the ___. what are 4 cellular roles of this effector molecule?

A

protein kinase A; increase heart rate and calcium, increase metabolism, increase hormone production

41
Q

___ is the mediator responsible for initiating the cellular changes that increase heart rate and contractility when epinephrine activates the beta-adrengeric receptors

A

protein kinase A

42
Q

another common G alpha protein is ___

A

G alpha I / Gi (inhibitory protein)

43
Q

G alpha I inhibits ____ and reduces the cellular production of __

A

adenyl cyclase; cAMP

44
Q

G alpha I has an inhibitory effect in cells that regulates activities of __ and __

A

second messengers and mediators

45
Q

provide an example of G alpha I receptors

A

M2 and M4 muscarinic receptors in the PNS

46
Q

activation of Gs and Gi receptors converge on __ , the enzyme that produces __

A

adenyl cyclase; cAMP

47
Q

when Gs and Gi are activated simultaneously, there will be ___ input into adenyl cyclase enzymes within a cell. why is this?

A

competing; because most cells in the body express many receptor types and it is possible that several are being modulated by endogenous molecules and drugs at the same time

48
Q

the overall cellular response when there are many competing inputs will be ___

A

the net integration of all the inputs

49
Q

t/f the observed physiologic response may be the result of many signalling pathways converging

A

true

50
Q

what is a third type od G-alpha protein?

A

Gq

51
Q

activated G alpha q enhances the activity of the cellular enzyme __

A

phospholipase c (PLC)

52
Q

Gq enhancing the activity of PLC increases the production of ___ an d__ by splitting the membrane phospholipid __

A

IP3 and DAG; PIP 2

53
Q

increased cellular levels of IP3 causes release of __ which promotes contraction of ___ and is also able to modulate other ___ and act as a ___

A

Ca2+; smooth muscle, proteins; second messanger

54
Q

DAG can activate other ___ and ___ such as __ to cause further intracellular changes

A

enzymes and kinase; protein kinase C

55
Q

give 2 examples of Gq coupled receptors

A

alpha 1 and the odd numbered muscarinic receptor

56
Q

t/f there are many more subtypes of Gbeta and Ggamma than G alpha, which results in a lot of combinations of G. beta gamma

A

true

57
Q

do the beta and gamma subunits remain together when the G protein dissociates from the receptor?

A

yes

58
Q

the extent of G beta gamma downstream effects are not as well __as for G alpha

A

described

59
Q

some key cellular effects of G beta gamma are the interactions and modulations of __ in __, which alters the __ of these cells

A

ion channels in neurons; excitability

60
Q

in order to regulate cellular response and prevent over stimulation, the activation of G-protein receptors also initiates a __

A

regulatory cascade to terminate the signalling response

61
Q

after the G protein dissociates, the receptor remains on the ____. Kinases called ____ phosphorylate the __ of the receptor, which prevents the association of another ___

A

cell surface, G-protein coupled receptor kinase (GRK); G-Protein

62
Q

receptor desensitization typically occurs within __ of exposure

A

minutes

63
Q

what is receptor desensitization?

A

cellular response to agonist declines (due to phosphorylation of receptors) even though the agonist is still present

64
Q

in receptor desensitization, the response will not go completely to __ when the agonist is still present, but will be significantly reduced

A

baseline

65
Q

___ binds to the phosphorylated tail of the inactivated complex, causing the receptor to be ___

A

beta-arrestin; internalized

66
Q

once internalized, what are the two options for the fate of a receptor?

A

can be recycled and brought back to the surface of cell or can be broken down by lysosomes

67
Q

if the cell decides to recycle a receptor, what 2 things have to be removed?

A

agonist and phosphate groups

68
Q

the brief periods of agonist exposure with periods of none present promotes receptor ___ and ____ of the cell

A

recycling and desensitization

69
Q

what is desensitization of receptors?

A

the receptors that have been recycled are moved back to the surface when no agonist is present, and will be ready to accept more if it comes

70
Q

if the cell is being overstimulated, what is it likely to do with the internalized receptors?

A

break them down in lysosome

71
Q

process of moving receptors to the cell surface is called __

A

receptor traficking

72
Q

if the cell has fewer receptors available, even after a period of no agonist, when the agonist comes back, the response may be ___ this is a hallmark of __

A

smaller; receptor downregulation

73
Q

when a cell chooses to break down its receptors, the full response cannot be achieved agin until___

A

new receptors are made

74
Q

the majority of our considerations of the actions of drugs will be based on which step of the G-protein life cycle ?

A

the first, agents binding to receptor and initiation of response

75
Q

___ exposure to agonist promotes quick turn around times between desensitization and resensitization, which promotes repeated physiologic responses

A

brief

76
Q

___ exposure to agonist promotes ___ of receptor to prevent overstimulation

A

long; down regulation

77
Q

t/f there are any druggable targets which are not receptors

A

true

78
Q

cellular enzymes are important drug __

A

targets

79
Q

give 2 examples of drugs that target enzymes and how they work

A

ACE inhibitors that reduce blood pressure by decrease enzyme production of angiotensin. 2) cyclooxyrgenase inhibitors have anti-inflammatory effects by reducing the synthesis of inflammatory mediators

80
Q

give 2 examples of drugs that do not have a specific target but rather change the physiologic environment

A

antacids that act by simple acid-base chemistry to neutralize stomach and 2) osmotic laxatives attract water to be absorbed into the intestine to relive constipation

Pharmacology (49 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions