enzyme inhibitors Flashcards
what is enzyme inhibitor
molecule that binds to enzyme and decreases its activity
can be reversible or irreversible
comp
non comp
competitive inhibitors
structure similar to substrate
binds to active site and prevents substrate bind
no ESC no react no product
if increase substrate dec effect comp inhibitor by inc probability enzyme sub collision
high sub conc reach Vmax
non competitive inhibitors
structure not similar to substrate
binds to allosteric site and distorts 3d structure enzyme therefore no ESC no product
inc sub conc cannot reverse the inhibition
allosteric enzyme
binding of molecule to specific allosteric site either allow or prevent substrate bind to active site
end product inhibition
when end product (noncompetitive inhibitor) of metabolic pathway builds up and inhibits enzyme in first reaction
means metabolic process is self controlled
- excess product not made
- resources not wasted
inhibitiors in disease
uncontrolled reactions can be fatal
eg multiple sclerosis where immune syst destroys nerve cells causing paralysis
metabolic poison
inhibit action of enzymes
eg potassium cyanide irreversible inhibitor due to cov bonds
inhibits cytochrome c oxidase used in respiration
inhibitors as medicine
penicillin irreversible inhibits bacterial enzyme
aspirin irreversible inhibits site COX enzyme stop chemicals form that cause inflame and pain
inactive precursor
reversible inhibitor needs to be removed prior to activate enzyme
eg digestive enzymes
trypsinogen to trypsin in small intestine
pepsinogen to pepsin in stomach
what is allosteric activator?
activator must bind to allosteric site to enable substrate to bind active site
what is allosteric inhibitor
allosteric inhibitor binds to allosteric site preventing bind sub to active site
