Enzymes as a drug target

Question 1

what is a cofactor

Answer 1

inorganic molecule or ion that helps the substrate to bind which is not changed in the reaction

Question 2

what is coenzyme

Answer 2

organic and are changed in a section

Question 3

what is compartmentalisation

Answer 3

enzymes are stored in a place with a specific environment - unable to function outside this

Question 4

what is feedback inhibition

Answer 4

end product of a pathway inhibits an earlier stage of the same pathway
e.g. phophofructose - ATP inhibition

Question 5

kinases

Answer 5

catalyse the transfer of a phosphate group from high energy phosphate donating groups to specific substrates via phosphorylation

Question 6

dehydrogenase

Answer 6

remove hydrogen from substrate

Question 7

ligase

Answer 7

synthesis of 2 molecules

Question 8

protease

Answer 8

breaks peptide bonds by hydrolysis

Question 9

lipase

Answer 9

catalyses breakdown of lipid by hydrolysis

Question 10

phosphatase

Answer 10

uses water to break phosphoric acid into phosphate ion and alcohol

Question 11

3 factors affecting enzyme action

Answer 11

temperature
PH
substrate concentration

Question 12

what is competitive E inhibition

Answer 12

similar shape to substrate, compete to bind at AS, depends on conc

Question 13

what in non-competitive E inhibition

Answer 13

bind to E on allosteric site, conformational change

Question 14

what is IC50

Answer 14

the half maximal concentration is the measure of effectiveness of a substrate in inhibiting a specific function

indicates how much drug is needed to inhibit a biological process by half

Question 15

what do steroids inhibit

Answer 15

phospholipases

conversion to archicionic acid formation so no COX formed

Question 16

what do COX 1 and Cox 2 inhibitors inhibiters such as aspirin

Answer 16

cycloxygenases which catalyse 1st 2 steps in biosynthesis of prostaglandins

Question 17

How do NSAIDS work

Answer 17

reduce the production of prostaglandins, chemicals that promote inflammation, pain and fever. The enzymes that produce prostaglandins are called COX
block the COX enzymes

Question 18

what does COX 1 produce

Answer 18

prostaglandins that activate platelets and protect the stomach and intestinal lining

Question 19

what happens when a drug inhibits the action of the enzyme of cox-1

Answer 19

it will recur inflammation but may also decrease the natural protective mucus lining of the stomach. (bleeding and ulcers)

Question 20

what does cox 2 do

Answer 20

production of prostaglandins that mediate pain and support the inflammatory process

Question 21

what is a prostaglandin

Answer 21

chemicals that promote inflammation pain and fever

Question 22

Which COX does aspirin inhibit more strongly

Answer 22

COX-1

Question 23

which drug does naproxen inhibit more strongly

Answer 23

COX-2

Question 24

which prostaglandin keeps the ductus arteriousus open and is involved in termination of pregnancy

Answer 24

PGE2- mediates pain, inflammation and fever and vasodilation and increased vascular permeability

Question 25

which prostaglandin is produced by mast cells and recruits TH2 cells and eosinophils and basophils

Answer 25

PGD2

Question 26

is prostacyclin a vasodilator ?

Answer 26

yes

also inhibits platelet aggregation

Question 27

TXA2 thromboxane is produced by active platelets what does it do

Answer 27

vasoconstriction

promotes platelet aggregation