conc. v effect graphs and relationships

Question 1

describe the relationship between the agonist conc. and receptor occupancy, as well as the shape of the graph on linear plot

Answer 1

as agonist conc. increases, receptor occupancy increases

hyperbolic graph on linear plot

Question 2

describe the relationship between agonist conc. and effect, as well as shape on linear plot

Answer 2

as agonist conc. increases, effect increases

hyperbolic on linear plot

Question 3

what is meant by EC50 (50 in subscript)

Answer 3

EC50 = the conc. of agonist that results in half of the maximal effect

Question 4

describe the relationship between the conc. of the agonist and the effect in a semi-logarithmic plot

Answer 4

as one increases other increases

shape = sigmoidal (shallow S shape)

Question 5

what is meant by the term potency and how would it relate to an effect against agonist conc. graph

Answer 5

potency = the ability of a drug to produce the desired effect
the more potent the agonist the less conc. needed to increase effect

Question 6

describe the effects of competitive and non-competitive antagonists on the graphs of agonist conc. against effect

Answer 6

competitive = causes parallel rightward shift of graph, maximum effect is unchanged
non-competitive = does not cause rightward shift, but lowers maximum effect and depresses the slope

Question 7

describe the effect of increasing the conc. of competitive antagonist on the graph of agonist conc. against effect

Answer 7

as antagonist conc. increases = progressive right ward shift of curve, no change to slope of maximum

Question 8

describe the effect of increasing the conc. of non-competitive antagonist on the graph of agonist conc. against effect

Answer 8

as antagonist conc. increases = progressive depression of maximum effect and slope, no shift of agonist conc. on x axis