enzymes Flashcards
oxidoreductases
REDOX rxns that involve the transfer of electrons
transferases move a
function group from one molecule to another
hydrolases catalyze
cleavage w/ the addition of water
lyases catalyze cleavage without
the addition of water and transfer of electrons
isomerases catalyze the interconversion of
isomers
including constitutional isomers + stereoisomers
ligases join two large
biomolecules often of the same type
lipases catalyze the
hydrolysis of fats
dietary fats are broken down into
fatty acids and glycerol/other alcohols
kinases add a
phosphate group
type of transferase
phosphatases remove a
phosphate group
type of transferase
phosphorylases introduce a
phosphate group into an organic molecule (notably glucose)
exergonic rxn
RELEASE energy
gibbs free E = negative
endergonic rxns
require energy
gibbs free E = positive
enzymes do not alter the
gibbs free E or enthalpy or the final equilibrium position
enzymes only alter the
changing the rate of the reaction
as substrate increases, so does the
rxn rate until a max value is reached
K is the [S] at which an enzyme…
runs at half its Vmax
Vmax is the max rate at which an enzymes can….
catalyze a rxn
all enzyme active sites are saturated w/ substrate
cooperative enzymes display what kind of curve
sigmoidal curve b/c of activity change with substrate binding
enzymes stabilize the
transition state
enzymes provide a favorable microenvironment and/or…
bonding w/ the substrate molecules
site of catalysis is called
the active site
lock and key theory
enzyme and substrate are complementary and fit together like a key into a lock
induced fit theory is where the enzyme and substrate…
undergo conformational changes to interact fully