Internal Med

Question 1

A receptor is ____ and is typically a

Answer 1

Component on or within a cell that a substance can bind to, typically a transmembrane protein

Question 2

Surface receptors are primarily responsive to?

Answer 2

specific amino acid, peptide, or amine compounds.

Question 3

Surface receptors can act 3 ways:

Answer 3

1. Act as ion channel altering membrane permeability
2. Act enzymatically to influence function of cell
3. Links to regulatory proteins that control other chemicals or enzymes

Question 4

What is an example of an ion channel receptor

Answer 4

Acetylcholine in the Neuromuscular junction, and GABA in the CNS

Question 5

The catalytic domain of a protein is found _____ whereas the binding domain is _____

Answer 5

Catalytic - inside the cell

Binding domain - outside the cell

These are for surface receptors directly linked to enzymes

Question 6

What is a receptor-enzyme example?

Answer 6

Tyrosine Kinase protein for insulin

Question 7

The process by which a signal on the cells surface is converted to a specific cell response

Answer 7

Transduction pathway

Question 8

Inhibitors effect the… and can be found….

Answer 8

effect the transduction pathway and are commonly found in cytoplasm

Question 9

G protein-coupled receptors allow for a

Answer 9

Sustained influence, because drug may only bind for short time but the G protein continues to stay active

Question 10

What is an example of a GPCR

Answer 10

adenylate cyclase-cyclic adenosine monophosphate (cAMP)

Question 11

Intercellular receptors are usually located

Answer 11

cytoplasm and/or the nucleus

specific to endogenous hormones or hormone-like drugs

example: steroids, thyroid hormones

Question 12

Affinity in a drug means

Answer 12

The amount of attraction between a drug and a receptor

Affinity is related to the drug amount that is required to bind to unoccupied receptors

Question 13

What influences affinity?

Answer 13

local regulators (i.e., allosteric modulators) and environments (membrane’s fluidity and organization)

Question 14

Agonists are drugs with

Answer 14

both affinity (they bind to the target receptor) and intrinsic efficacy (they produce a response)

Question 15

Antagonists are drugs with

Answer 15

Antagonists have affinity but zero intrinsic efficacy; therefore they bind to the target receptor but do not produce a response

Question 16

A competitive antagonist….

Answer 16

competes for the same binding spot as the agonist

Question 17

A noncompetitive antagonist….

Answer 17

Binds somewhere else but still inhibits agonists ability to bind to it’s specific sites

Question 18

An inverse agonist…

Answer 18

binds to the same receptor as the agonist, but produces an opposite effect to that of the agonist

Question 19

Drug Selectivity influences…..

Answer 19

Side-effects (when it binds to unintended sites) vs being selective with where it binds

Question 20

drug selectivity example

Answer 20

the cholinergic receptor found on various tissues throughout the body.

Nicotine binds to just one type, whereas Acetylcholine binds to two

Question 21

Dose Response Curve is typically

Answer 21

proportional to the number of receptors occupied by the drug (not a linear relationship)

Question 22

Increasing a dose beyond the dose response curve…

Answer 22

will not produce any more effect because all receptors are already bound by the drug

Question 23

When competitive agonist and antagonist are present….

Answer 23

Whichever drug concentration is higher, predominant effect

Question 24

non-competitive antagonists are only terminated by

Answer 24

normal protein turnover, so effect tends to be long

Question 25

partial agonist

Answer 25

Strong agonist = 100% efficacy
& Strong antagonist = 0% efficacy
Partial agonist = 1~99 % efficacy
-it does NOT COMPLETELY ACTIVATE the receptor after it binds

Question 26

Mixed agonist-antagonist

Answer 26

-Will act as an agonist on one tissue/organ
-Will act as an antagonist on another tissue/organ

Question 27

What is an example of a mixed agonist antagonist?

Answer 27

Selective estrogen receptor modulators can act as an agonist on bone and an antagonist on breast tissues

Question 28

inverse agonist can decrease….

Answer 28

activity where the receptor is too active or overstimulated

Question 29

overstimulation of postsynaptic receptors by endogenous substances or by exogenous agonists may lead to

Answer 29

Functional decrease in appropriate receptor population

Question 30

a prolonged decrease in the stimulation of the post-synaptic receptors can result in a ______ in receptor sensitivity

Answer 30

Functional increase to compensate

Question 31

What are the negative feedback mechanisms to prevent overstim by agonist?

Answer 31

Desensitization - (Brief and Transient) Within few minutes sensitivity returns to normal after they unbind

Receptor internalization- Receptors are withdrawn from cell membrane by endocytosis

Down Regulation- (slow and prolonged) Increased receptor removal and decreased receptor synthesis or BOTH

Question 32

Which one is brief and which one is slow and prolonged?

Down-Regulation

Desensitization

Answer 32

Desensitization - Brief- few minutes

Down-Regulation- Slow ( remains for a few days after agonist is gone

Question 33

Receptor Supersensitivity can occur if

Answer 33

You’re taking receptor antagonist drugs for prolonged periods of time (they adapt to it), the neuron interprets this as the synapse being denervated and responds by making more receptors.

Question 34

Denervation in PNS, Lack of neurotransmitter release results in what kind of compensation

Answer 34

Receptor Supersensitivity

Question 35

Parkinson disease is….

Answer 35

Loss of the endogenous NT dopamine result in super-sensitivity of receptors for that neurotransmitter