Flashcards in L4 enz activ: kinetics and inhib Deck (5)
LO2: how reac rate vary as func of E and S conc. V vs [S] graphs. enz kinetics.
- enz optim temps and ph. Vo init rate. max velocity, rectang hyperbola.
LO3: define activity, internat unit of enz activ, Km and Vmax. MM mod enz ctal.
- MM proposes specif complex btw E and S necess intermed in catal. V0=Vmax[S]/Km+[S]. Km=michaelis const. Vmax= max velocity mol/min. predicts hyperbol V0 vs [S], not all enzs obey eg if show coop.
Vmax= max rate when all enz AS sat, very dep on [enz].
Km= [S] that gives half max velocity.
LO4: anal and interp kinetic data for enz catal reac. work out rates. apply Km and Vmax.
- Km meas affin of E for S. low Km=high affin. high Km=low. eg HK higher affin for gluc than GK.
- linewaver burk plot- recip of MM=straight line. y intercept=1/Vmax so higher= low Vmax. x intercept=-1/Km so lower=lower Km= higher affin.
- Vmax is meas of amnt per unit time. 1 unit= amnt of enz that convs 1umol of prod per min stand conds. often exp as stand rate- per L serum or g tiss. rate propor to [enz].
LO5: desc effs of enz inhibs on enz kinetics and disting by graphs. how alt shape of V vs [S] or linewaver, and determ type inhib from these.
- inhibs prev/slow enz reac eg drugs.
irrev bind v tight, gen cov eg nerve gas sarin.
rev non cov, freely dissoc. comp bind AS aff Km NOT Vmax as overcome by incr [S], decr propor E bound to S, eg tamiflu. non comp bind other site but not allost, decr turnover so aff Vmax NOT Km.