1, Molecules and Receptors

Question 1

what is PHARMACODYNAMICS the STUDY OF

Answer 1

what a DRUG DOES TO the BODY

• BIOCHEMICAL and PHYSIOLOGICAL EFFECTS

& MECHANISMS of drug ACTION,
& the relationship between drug CONCENTRATION and EFFECT

Question 2

at basic equilibrium, AGONIST-RECEPTOR COMPLEX CONC. [AR] is PROPORTIONAL to..

Answer 2

CONC. AGONIST (drug) [A]
and CONC. RECEPTOR [R]

Question 3

[AR] =

Answer 3

[AR] = K affinity [A][R]

(affinity constant for A, ability of receptor to bind agonist)

Question 4

K affinity =

Answer 4

[AR] / [A][R]

Question 5

[A][R] =

Answer 5

[A] [R] = Ka [AR]

KA is DISSOCIATION CONSTANT for agonist

Question 6

K a =

(dissociation constant)

Answer 6

[A] [R] / [AR]

Question 7

what does HIGH AFFINITY mean for K a (dissociation constant)

Answer 7

LOW KA

KA = [A][R] / [AR]

high affinity means high [AR]

Question 8

Y is the proportion of receptors occupied and 1 means all receptors are bound
what is the equation for Y
y=

Answer 8

y = 1
/ 1 + Ka/[A]

Question 9

when does Ka = [A]

Answer 9

when y=0.5

Question 10

a DOSE RESPONSE CURVE for an AGONIST is a … curve

Answer 10

HYPERBOLIC CURVE

(increases and curves off)

Question 11

a LOG-DOSE RESPONSE CURVE for an AGONIST is a … curve

Answer 11

SIGMOIDAL CURVE

(s shape)

Question 12

what can be measured directly from a LOG-CONCENTRATION RESPONSE CURVE

Answer 12

EC50
- CONC at 50% RESPONSE