pharmacodynamics: target tissue receptors

Question 1

what is a receptor

Answer 1

component on or within a cell that a substance can bind to

Question 2

when a drug binds to the receptor

Answer 2

it initiates a biochemical chain of events

Question 3

receptor that recognize as endogenous and exogenous compounds often have a ..

Answer 3

binding site on the outer surface of the cell membrane

Question 4

what are many surface receptors ?

Answer 4

transmembrane proteins

Question 5

surface receptors act as an

Answer 5

ion channel and directly altering membrane permeability

Question 6

receptors become an

Answer 6

ion pore and change the membrane permeability
ex: acetylcholine receptor

Question 7

what is found on neuronal membranes in the CNS

Answer 7

GABA

Question 8

drugs and endogenous chemicals that bind to the receptor side can..

Answer 8

change the enemy me activity of the intracellular catalytic compound ; thus changing the biochemical function within the cell

Question 9

common example of a receptor enzyme system

Answer 9

receptor tyrosine kinase protein

Question 10

surface receptors linked to regulatory (G) proteins

Answer 10

affect the cell function by linking to an intracellular intermediate regulatory protein (g protein), activated by binding guanine nucleotides

Question 11

when a druge attaches to a G protein what happens

Answer 11

alters the activity of an intracellular effector ; leading to change in cell function

Question 12

how does the drug act as a first messenger when linked to a G protein

Answer 12

it triggers a biochemical change in the cell but the drug itself does not enter

Question 13

what does the secondary messenger do when a surface receptor is linked to a G protein?

Answer 13

it is the substance produced inside the cell, actually mediated the change in function

Question 14

what is the primary example of secondary messenger

Answer 14

adenylate cyclase cyclic adenosine monophosphate (cAMP)

Question 15

adenylate cyclase is responsible for hyrolyzing adenosine triphosphate into

Answer 15

cAMP

Question 16

where are intracellular receptors located

Answer 16

within the cytoplasm and/or nucleus

Question 17

what are intracellular receptors specific for ?

Answer 17

certain endogenous hormones and hormone like drugs
ex: steroids

Question 18

the drugs ability to bind to any receptors depends on

Answer 18

the drugs size and shape relative to the confirguation of the receptors binding site

Question 19

define affinity

Answer 19

the amount of attraction between a druge and a. receptor

Question 20

what is affinity related to ?

Answer 20

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

Question 21

a drug with high affinity ..

Answer 21

binds readily to the open receptors , even if the concentration of the drug is low

Question 22

drugs with moderate or low affinity require a

Answer 22

higher concentration in the body before the receptors become occupied

Question 23

what are allosteric modulators

Answer 23

local receptors that are distinct from the primary binding site and there by increase or decrease the affinity for the drug

Question 24

what is affinity influenced by ?

Answer 24

local regulators (allosteric modulators) and environments (membrane fluidity and organization)

Question 25

a drug is sadi to be selective if

Answer 25

it affects only one type of cell or tissue and produces a specific physiological response

Question 26

the fact that we can classify many receptors into subtypes means we can develop

Answer 26

drugs that will affect only one receptors subtype and therefore produce fairly selective effected with few side effects

Question 27

the dose response is

Answer 27

related to the number of receptors that are bound by the drug

Question 28

the dose response is typically

Answer 28

proportional to the number of receptors occupied by the drug
not linear

Question 29

agonist drugs

Answer 29

has both affinity and efficacy

Question 30

antagonist drugs

Answer 30

has only affinity and it occupies the celeste to block the effect of another chemical (bad guy)

Question 31

define drug efficacy

Answer 31

indicated that the drug will activate the receptor and change the function of the cell

Question 32

competence antagonists

Answer 32

vie for the same receptor as agonist
equal opportunity
whichever drug concentration is higher
agonist can overcome the antagonist

Question 33

no competitive antagonist

Answer 33

irreversible bonds
inability of agonist to compete with anatagonist
terminated only with normal protein turnover

Question 34

drugs that do not evoke a maximal response compared to a strong agonist is called

Answer 34

partial agonist , they occupied all availed receptors

Question 35

what is it called when some agents will similar certai receptors subtypes while simultaneously black the effects of endogenous suzanne’s on other receptor subtypes

Answer 35

mixed agonist antagonist

Question 36

Overstimulation of postsynaptic receptors may lead to a decrease in responsiveness of the receptors. A fairly brief and transient decrease in receptor responsiveness is known as _____, whereas a more prolonged process in which the actual number of available receptors is diminished is known as _________.

Answer 36

desensitization: down regualtions

Question 37

define receptor internalization

Answer 37

receptors are withdrawn from the cell membrane by endocytosis

Question 38

define down regulation

Answer 38

describes a slower, more prolonged process in which the number of availed receptors is diminished