1Enzyme Kinetics
the study of reaction rates that are catalyzed by a purified enzyme
2Michaelis Menten Equation
V0= (vmax[S]) / (Km + [S])
3Binding Step
forward is K1, backward is K-1
E+S <---> ES
4Catalytic step
kCat (turnover number)
ES --> E+P
5Lower Km indicates
tighter and higher affinity for ES
6Kcat
# of molecules in a given time when enzyme is saturated with substrate
7We assume that ES is _______ in the Michaelis Menten Equation
constant
8Michaelis Constant formula
Km= (k-1+ kcat) / k1
9Y intercept and X intercept of Lineweaver-Burk plot
Y intercept = 1 / (V max)
X intercept = - 1 / Km
10High Km
leads to enzyme being idle
12Km
substrate concentration that is needed to achieve half of Vmax
13Kcat/Km: : catalytic efficiency
The ratio Kcat/Km combines information about how fast bound substrate is processed and how well substrate is captured
14Catalytic Perfection
- every collision between enzyme and its substrate is productive
- the rate is only limited by the frequency of collision between the enzyme and its substrates