enzyme kinetics Flashcards
velocity MM assumption
[EP] and [p] low, so k-2 and k-3 negligible
what happens in the MM reaction to cause it to go linear to hyperbolic
substrate concentration goes down
product assumption of MM
k3 fast compared to k2
rate of product release is fast
mm assumption about ss
reaction at steady state
[ES] is held constant
and rates of [ES] formation and loss are equal
michaelis constant units
molar
what does vmax depend on
enzyme concentration and rate of the rxn
how to increase vmax
increase enzyme
lbp y intercept
1/vmax
lbp x intercept
(-1/km)
lbp y axis
1/v0
lbp x axis
1/[s]
km definition
concentration of substrate which permits the enzyme to achieve 1/2 vmax
kcat is equal to
k2
large [s] means
k1 step is not limiting, and all E is in ES
when [s] is less than km, this reduces to
(kcat/km)[etotal][s] = v0
kcat/km units
m-1 s-1
kcat/km meaning
catalytic efficiency, how often encounters between enzyme and substrate o cur that form product
diffusion limit
maximal rate of transport of substrate molecules in solution
catalytic perfection
substrate converted to product as fast as it can diffuse into the enzyme
kcat/km
km is ____ component
thermodynamic
kcat is the _____ component
kinetic
catalytic perfection
substrate converted to product as fast as it can diffuse into the enzyme
catalytic perfection equation
10^8 to 10^9 m-1 s-1
type of bonds in irrevesrsible enzyme inhibition
covalent
type of bonds in reversible enzyme inhibition
noncovalent
competitive inhibitors resermble
substrates
does the competitive inhibitor affect km or vmax
km
what effect does high [s] have on competitive inhibition
can outcompete
compeittive inhibitions results in a ____
higher kd
where does the inhibitor bind in uncompeittive inhibition
enzyme-substrate
which parameters does an uncompetitive inhibitor affect an enzyme’s kinetic parameters?
vmax and km
uncompet inhib what happens to km
decreases
uncompet inhib what happens to vmax
decreases
what effect does high [s] have on uncompetitive inhibition
none
