Enzyme Kinetics

Question 1

What is the Michaelis-Menten equation?

Answer 1

V=(Vmax *[S])/Km + [S]
V=initial reaction velocity 
Vmax= maximal velocity
Km = Michaelis constant 
S=substrate concentration

Question 2

What are the different reactions rate of the Michaelis-Menten equation?

Answer 2

First order reaction :
When [S] &laquo_space;Km –>V=(Vmax*[S])/ Km
Zero order reaction:
When [S]&raquo_space; Km –>v=Vmax

When [S] =Km–> V =Vmax/2

Question 3

What is the affinity of the enzyme based on the Km?

Answer 3

Small Km —>high affinity of enzyme for the substrate

Large Km —> Low affinity of enzyme for the substrate

Question 4

What is the turnover number?

Answer 4

Kcat is the number of product released per unit time per enzyme at Vmax
Vmax= Kcat[E total]
The higher the Kcat , the better

Question 5

What is the Lineweaver-Burk plot?

Answer 5

Double reciprocal plot switch the right hyperbola of the Michaelis-Menten equation to a straight line
(1/V)= (Km/Vm *[S]) + 1/Vm
Y-intercept= 1/Vmax
X-intercept= -1/Km
Slope= Km/Vmax