kinetics/dynamics

Question 1

michaelis-Menton eq

Answer 1

V=(Vmax*[S])/(Km+[S])

Question 2

Km (inverse of affinity/potency)

Answer 2

[S] at which V=1/2 Vmax. inversely related to affinity. [E[ has no effect. increased by competitive reversible inhibitors.

Question 3

Vmax (efficacy)

Answer 3

Vmax=k2*[E]. V when [S]»»Km. [S] has no effect. decreased by competitive irreversible and non-competitive inhibitors.

Question 4

Lineweaver-Burke plot

Answer 4

verticle: 1/Vmax
horizontal: 1/-Km or 1/[S].
inhibitors: competitive cross, noncompetitive do not.

Question 5

`substrate limited

Answer 5

[S]c dependent, first order.

Question 6

enzyme imited

Answer 6

[S]»>Km. con’c independent. zero order.

Question 7

volume of distribution

Answer 7

Vd= amount of drug in body/plasma drug con’c

Question 8

half life

Answer 8

T1/2= 0.693*Vd/ CL

Question 9

Clearance

Answer 9

CL= rate of eliminating drug/plasma drug con’c

Question 10

loading dose

Answer 10

=target plasma con’c * Vd/ bioavailability

Question 11

maintenance dose

Answer 11

= target plasma con’c * CL * dosage interval / bioavailability

Question 12

therapeutic index

Answer 12

TD50/ED50= median toxic dose/median effective dose. higher is safer.