Drug Targets

Question 1

what is Km?

Answer 1

the substrate concentration at which the reaction velocity is half maximum
Km gives an indication of how tightly the enyme binds its substrate

Question 2

what does a large Km indicate?

Answer 2

a high [S] is needed to acheive Vmax/2
weak substrate

Question 3

what does a low Km indicate?

Answer 3

only a ow [s] is needed to reach Vmax/2
good substrate

Question 4

what happens when using enzyme targeting drugs?

Answer 4

these drugs prevent enzymes from catalysing their reaction on the substrate which leaves the drug action altered metabolism

Question 5

what are irreversible enzyme inhibitors?

Answer 5

bind covalently to n enzyme, or form a highly stable non-covalent asscociation (tight-binding inhibitors)

Question 6

what are reversible enzyme inhibitors?

Answer 6

diffuse in and out of enzymes

Question 7

what are the 3 main types of reversible enzyme inhibitors?

Answer 7

competitive
uncompetitive
mixed

Question 8

what are competitive inhibitors?

Answer 8

bind the same site of the substrate and prevent the substrate from binding

Question 9

what are uncompetitive inhibitors?

Answer 9

bind to the ES complex, they usually bind a different site to the substrate but not the active site

Question 10

what are mixed inhibitors?

Answer 10

present a combination of competitve and uncompetitive inhibitors
always decrease Vmax, but can increase or decrease Km, depending on relative values

Question 11

how can we design an agonist?

Answer 11

the drug must have the correct binding groups
the drug must have these binding groups corrrectly positioned
the drug must have the right size for the binding site

Question 12

what are partial agonists?

Answer 12

compounds act as an agonist and produces a biological effect, but that effect is not as great as one would get with a full agonist

Question 13

what is affinity?

Answer 13

Affinity of a drug for a receptor is a measure of how strongly that drug binds to the receptor. Affinity constant (Ki )

Question 14

what is efficacy?

Answer 14

a measure of the maximum biological effect that a drug can produce as a result of receptor binding

Question 15

what is potency?

Answer 15

Potency of a drug refers to the amount of drug required to achieve a defined biological effect—the smaller the dose required, the more potent the drug. It is possible for a drug to be potent (i.e. active in small doses) but have a low efficacy