Enzymes as a drug target Flashcards
(27 cards)
what is a cofactor
inorganic molecule or ion that helps the substrate to bind which is not changed in the reaction
what is coenzyme
organic and are changed in a section
what is compartmentalisation
enzymes are stored in a place with a specific environment - unable to function outside this
what is feedback inhibition
end product of a pathway inhibits an earlier stage of the same pathway
e.g. phophofructose - ATP inhibition
kinases
catalyse the transfer of a phosphate group from high energy phosphate donating groups to specific substrates via phosphorylation
dehydrogenase
remove hydrogen from substrate
ligase
synthesis of 2 molecules
protease
breaks peptide bonds by hydrolysis
lipase
catalyses breakdown of lipid by hydrolysis
phosphatase
uses water to break phosphoric acid into phosphate ion and alcohol
3 factors affecting enzyme action
temperature
PH
substrate concentration
what is competitive E inhibition
similar shape to substrate, compete to bind at AS, depends on conc
what in non-competitive E inhibition
bind to E on allosteric site, conformational change
what is IC50
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
what do steroids inhibit
phospholipases
conversion to archicionic acid formation so no COX formed
what do COX 1 and Cox 2 inhibitors inhibiters such as aspirin
cycloxygenases which catalyse 1st 2 steps in biosynthesis of prostaglandins
How do NSAIDS work
reduce the production of prostaglandins, chemicals that promote inflammation, pain and fever. The enzymes that produce prostaglandins are called COX
block the COX enzymes
what does COX 1 produce
prostaglandins that activate platelets and protect the stomach and intestinal lining
what happens when a drug inhibits the action of the enzyme of cox-1
it will recur inflammation but may also decrease the natural protective mucus lining of the stomach. (bleeding and ulcers)
what does cox 2 do
production of prostaglandins that mediate pain and support the inflammatory process
what is a prostaglandin
chemicals that promote inflammation pain and fever
Which COX does aspirin inhibit more strongly
COX-1
which drug does naproxen inhibit more strongly
COX-2
which prostaglandin keeps the ductus arteriousus open and is involved in termination of pregnancy
PGE2- mediates pain, inflammation and fever and vasodilation and increased vascular permeability
