Drugs and receptors

Question 1

what is a receptor

Answer 1

part of a cell that interacts with a specific ligand and initiates a change of biochemical events leading to ligand observable effects

Question 2

what classes of chemicals can receptors communicate with

Answer 2

Neurotransmitters
Autacoids
Hormones

Question 3

What type of receptors are there

Answer 3

Ligand gated ion channels

G protein-coupled receptors

Kinase linked receptors

Cytosolic/nuclear receptors

Question 4

What are G protein-coupled receptor? (GPCR)

Answer 4

Family of proteins involved in transmitting signals from GPCR’s

Question 5

what binds to and hydrolised GTP and GDP (guanine triphosphate + Guanine diphosphate

Answer 5

G proteins (gioamome. nucleotide-binding-proteins)

Question 6

what is a kinase

Answer 6

Enzymes that catalyse the transfer of phosphate groups

Question 7

What is a nuclear receptor and how do they worl

Answer 7

Steroid hormone receptors

Worryk by modifying gene transcription

has zinc fingers that bind to DNA

Question 8

what type of cancer is tamoxifen used

Answer 8

Estrogen receptor+ cancers

Question 9

give an example where an inbalance in chemicals can lead to a pathology

Answer 9

Allergy –> inc histamine

Parkinsons –> reduced histamine

Question 10

Give and example where an imbalance in receptor can lead to a pathology

Answer 10

Myasthenia gravis – loss of ACh receptors

Mastocytosis –> increased c-kit receptor

Question 11

What is an agonist

Answer 11

a compound that binds to a receptor and activated it

Question 12

what is an antagonist

Answer 12

• A compound that reduces the effect of an agonist
• Affinity but not efficacy

Question 13

give the equation for intrinsic activity

Answer 13

intrinsic activity = Emax of partial agonist / Emax of full agonist

Question 14

What does intrinsic activity mean

Answer 14

the ability of a drug-receptor complex to produce a maximum function response

Question 15

what is selective agonism

Answer 15

potency of a range of agonists

Question 16

What is selective antagonism

Answer 16

competitive antagonists

Question 17

is nicotine nad agonist or antagonist

Answer 17

agonist

Question 18

What are all the histamine receptors characterized as

Answer 18

H1 = allergy
H2 - Gastric acid secretion
H3 = Monstly CNS disorders (narcolepsy, ADHD, alzheimers)
H4 = immine system and inflammatory conditions (asthma, arthritis)

Question 19

wgat is effacacy

Answer 19

Described how well a ligand activates the receptor

Question 20

T/F agonists have no affinity but have effacacy

Answer 20

F
Agonists Have affinity and efficacy

Question 21

T/F antagonists have affinity but no efficacy

Answer 21

T

Question 22

what is an irreversible antagonist

Answer 22

irreversibly dound to a receptor

Question 23

Define inverse agonism

Answer 23

drug that binds to the same receptor as an agonist but induces a pharmacological response opposite to that of an agonist

Question 24

Describe tolerance

Answer 24

-Reduction in agonist effect over time
-continuously, repeatedly, high cons

Question 25

Descripe desensitization

Answer 25

Uncouples, internalized, degraded

Question 26

what are the passive ion transporters

Answer 26

Symporters and channels

Question 27

What are the active ion treansporter

Answer 27

ATP-ases

Question 28

**Competitive** agonists are a) **Surmountable** and **irreversible** b)**surmountable** and **reversible** c)**insurmountable** and **irreversible** d)**insurmountable** and **reversible**

Answer 28

b

Question 29

**Non competetive** agonists are a) **Surmountable** and **irreversible** b)**surmountable** and **reversible** c)**insurmountable** and **irreversible** d)**insurmountable** and **reversible**

Answer 29

C

Question 30

what is the difference between a **Full, partial** and **Inverse** **AGONIST**

Answer 30

Full agonist: **high efficacy**, produces** full respons**e while **occupying** a relatively **low amount of receptors.** **Affinity but efficacy ** -Partial agonist: **lower efficacy** than a full agonist. It produces **sub-maximal activation** even **when occupying the total receptor population**; therefore **cannot produce the maximal response**, irrespective of the concentration applied. **Won't reach eMax** -Inverse agonist: effect **opposite to that of an agonist**, yet **binds to the same receptor binding site as an agonist **