Brainscape's Knowledge GenomeTM

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


See full index

Pharmacology > 1- Drug-Receptor Interactions > Flashcards

1- Drug-Receptor Interactions Flashcards

1
Q

What are drug receptors?

A

they’re macromolecules that, upon binding to a drug, mediate those biochemical and physiologic changes

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

What is that binding site of the drug?

A

The site on the receptor at which the drug binds

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

How is a drug receptor selective for a certain drug?

A

The 3-D structure, shape and reactivity of the site, and the inherent shape, structure and reactivity of the drug.

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

What is the affinity for a receptor?

A

It is the result of chemical interactions between the two molecules and the favorability of this interaction

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

What are covalent interactions?

A

They are very strong interactions between the drug and the receptor that they are essentially irreversible

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

What must the cell do if a drug binds to a receptor covalently forming an interactive complex?

A

It must synthesize a new receptor molecule to replace the inactivated protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How strong is ionic bonding?

A

Stronger than hydrogen bonds but weaker than covalent bonds

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

What is Van der Waal forces?

A

They provide weak attractive forces for drugs and their receptors

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

Is the interaction between a drug and a receptor the formation of only one type of bond?

A

No. Rarely is a drug receptor binding caused by a single type of interaction. Essentially multiple week forces comprise the majority of the drug receptor interactions

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

What is the 2 important reasons why enatiomers are important for drug receptor interactions?

A

Usually one form is a lot stronger than the other form, and sometimes one form is therapeutic and one form is toxic.

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

What is induced fit?

A

It’s when the binding of a drug to its receptor results in a change in confirmation of the receptor for better binding of the drug.

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

What is a good example of induced fit using an exogenous drug?

A

Exogenous insulin stimulates the insulin receptors to the same extent despite differences in amino acid sequences

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

Besides a tighter binding of the receptor to the drug induced fit, what other outcome might result?

A

Binding of the drug might make the receptor more or less functional than normal.

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

How might drug and receptor structures confer specificity on the interactions between drugs and their receptors?

A

Structure of the receptor determines where the protein is located in relationship to the cellular boundaries such as the plasma membrane

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

How can hydrophilic drugs passed through the Plasma membrane to get to cytoplasmic receptors?

A

Transmembrane channels

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

How can lipophilic drugs get to their intracellular targets?

A

Since they are fat-soluble they just pass right through the membrane.

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

What is the relationship between the Restriction of the receptor and side effects?

A

The more the restricted the receptor is, the more selective the drug is for the receptor and therefore fewer side effects

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

What is an example of a drug that is not very specific and therefore creates large side effects?

A

Drugs that have a general function such as DNA synthesis are likely to cause significant toxic side effects, Like chemotherapeutics for the treatment of cancer

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

Is a drug more or less selective if the receptor – defector coupling mechanisms differ among various cell types?

A

More selective

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

What is a partial agonist?

A

It’s a drug that produces a submaximal response upon binding to their targets

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

What is a competitive antagonist?

A

They are drugs that directly blocked the binding site of a physiologic agonist

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

What is an inverse agonist?

A

They’re drugs and that cause constitutively active targets to become inactive

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

What are noncompetitive antagonists?

A

They are drugs that bind to sites other than where the physiologic agonist binds and thereby prevents the confirmational change required for receptor activation

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

What are ligand gated channels?

A

They are channels that the conductance is controlled by a ligand binding to the channel

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

What are voltage gated channels?

A

They are channels in which conductance is regulated by changes in voltage across the membrane

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

What are second messenger regulated channels?

A

Their channels in which conductance is controlled by ligand binding to plasma membrane receptors that are links to the channel in someway

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

What is a very important ligand gated channel on muscle cells?

A

Nicotinic acetylcholine receptor

28
Q

What is the mechanism of local anesthetics?

A

They block voltage gated sodium channels

29
Q

What is the mechanism of action of benzodiazepines?

A

They inhibit neurotransmission by GABA to increase the conductance of chlorine ions across neuron membranes

30
Q

What is the most abundant class of receptors in human body?

A

G protein coupled receptors

31
Q

What is the fxn of the α subunit of the G-protein?

A

Exchange GDP for GTP and activating effectors

32
Q

Give the pathway of activations that occurs during α subunit binding to AC in Gs receptors

A

Ligand binds –> α subunit diffuses with GTP to adenylyl cyclase (AC) –> AC converts ATP to cAMP –> cAMP activates PKA –> protein phosphorylation

33
Q

Give the pathway of activations that occurs during α subunit binding to PLC in Gq receptors

A

Ligand binds –> α subunit with GTP binds to PLC –> IP3 and DAG made –> DAG activates PKC –> protein phosphorylation

34
Q

Generally, what is activated with Gs proteins?

A

Ca++ channels, Adenylyl cyclase

35
Q

Generally, what is activated with Gi proteins?

A

K+ channels, inhibits AC

36
Q

Generally, what is inhibits with Go proteins?

A

Ca++ channels

37
Q

Generally, what is activated with Gq proteins?

A

PLC

38
Q

Where are β1 receptors located?

A

Heart (SA node and myocardium), adipose tissue

39
Q

What are the effects of β1 activation?

A

increased HR, contractility of heart, lipolysis

40
Q

Where are the β2 receptors located?

A

Bronchial smooth muscle, GI, uterus, bladder, liver, and pancreas

41
Q

What are the effects of β2 activation?

A

Dilation of bronchioles, relaxation of gut, relaxes bladder and uterus, increases gluconeogenesis in liver, stimulates insulin release from pancreas

42
Q

What are the functions of transmembrane receptors with a cytoplasmic enzymatic domain?

A

transduce and extracellular ligand-binding interaction into an intracellular action through the activation of a linked enzymatic domain

43
Q

What are the main signals that bind to tyrosine kinase receptors?

A

Hormones and growth factors.

44
Q

What is the main mechanisms of how tyrosine kinase receptors work?

A

phosphorylation of tyrosine residues on the cytoplasmic tail of the receptor, leading to phosphorylation of a number of cytosolic signaling molecules

45
Q

Since tyrosine kinase receptors play a key role in cell growth/differentiation, mutations could cause what problems?

A

mutations in these receptors can lead to cancer and uncontrolled cell growth

46
Q

What types of enzymes remove phosphate groups from specific tyrosine residues?

A

tyrosine phosphatases

47
Q

What type of transmembrane receptors with a cytoplasmic enzymatic domain does TGF-β superfamily use?

A

Receptor serine/threonine kinases

48
Q

What is required for a ligand to bind to intracellular receptors?

A

It has to be lipid soluble to cross the plasma membrane

49
Q

Which lipophilic anticoagulant works by binding to enzymes in the cytosol (a type of intracellular R)?

A

warfarin

50
Q

Steroid hormones typically bind to intracellular receptors in which part of the cell?

A

Nucleus (they act as transcription factors)

51
Q

Extracellular enzymes have binding sites for drugs where in the body?

A

Basically anywhere outside the plasma membrane

52
Q

Give an example of an extracellular receptors that is used to lower blood pressure.

A

ACE Inhibitor drugs lower blood pressure. Angiotensin converting enzyme (ACE) converts angiotensin I –> angiotensin II (vasoconstrictor)

53
Q

Why can many different drugs produce the same effects via second messengers?

A

Because 2nd messengers provide cells with a set of common points upon which numerous outside stimuli could converge to generate a coordinated cellular effect

54
Q

What is signal integration?

A

When ligands bind to receptors that have opposite 2nd messenger effects, like activation of Gs receptors (which activates AC) and Gi receptors (which inhibits AC)

55
Q

What is homologous desensitization?

A

the effects of agonists at only one type of receptor are diminished

56
Q

What is heterologous desensitization?

A

the effects of agonists at two or more types of receptors are coordinately diminished

57
Q

What typically causes heterologous desensitization?

A

Caused by drug induced alteration in a common point of convergence in the mechanisms of action of the involved receptors, such as a shared effector molecule

58
Q

What is receptor inactivation?

A

completely turning off the receptor to stimulation by ligand.

59
Q

How does a receptor get inactivated?

A

Results from phosphorylation of the receptor

60
Q

What is the refractory of the receptor?

A

it’s the state following activation in which the receptor requires time before it can be stimulated again

61
Q

What is down-regulation of the receptor?

A

a molecular mechanism in which the receptor NUMBER can be altered

62
Q

What is the general mechanism of receptor down-regulation?

A

prolonged receptor stimulation by ligand induces the cell to endocytose and sequester receptors in endocytotic vesicles. Once the stimulus that caused the down-regulation is gone the receptors can be recycled back up to the cell surface to be used again

63
Q

What are 2 classes of drugs that lack receptors?

A

osmotic diuretics and antacids

64
Q

What is mannitol?

A

Osmotic diuretic

65
Q

What is the mechanism of action of mannitol?

A

Secreted into the lumen of the nephron and increases the osmolarity of the urine to such a degree that water is drawn from the peritubular blood into the lumen.

66
Q

What is the mechanism of action of antacids?

A

Act nonspecifically by absorbing or chemically neutralizing stomach acid

Pharmacology (9 decks)

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