Lecture 10: mechanisms of catalysis Flashcards
transition state = (higher/ lower) energy state
higher energy state
stabilizing the t state will (inc/ dec) rate of the rxn
increase rate
2 ways to stabilize t state
- protonate carbonyl oxygen making carbonyl carbon more electrophilic [acid catalysis]
- deprotonate H2O making O more nucleophilic [base catalysis]
metal ion catalyst
electrostatic stabilization of a charged group in the t state
when Vo is higher at lower pH, His is
protonated [acid catalysis]
when Vo is lower at lower pH, His is
deprotonated [base catalysis]
the pH-rate profile of an enzyme-catalyzed reaction will affect ionization states of
all species [enzyme and substrate] in the rate limiting t-state
chymotrypsin
endoprotease that functions during intestinal digestions; cleaves both proteins and esters
the intermediate of chymotrypsin-catalyzed hydrolysis of an ester is
between burst and steady phase; not active