Enzyme Kinetics Flashcards
Describe the term V
rate of the catalysed reaction
Describe the term Vmax
Vmax is the maximum velocity or rate at which the enzyme catalyzed a reaction. It happens when all enzyme active sites are saturated with substrate
Describe the term k
rate constant of the reacion
Describe the term k1
the forward rate constant for enzyme association with the substrate
Describe the term k-1
the backward rate constant for enzyme dissociation from the substrate
Describe the term k2
the forward rate constant of enzyme conversion of substrate to product
Give the equation for the term Km, Michaelis constant
k-1+k2/k1
What is the Michaelis constant Km equivalent to?
Km is equivalent to the substrate concentration where the initial reaction rate is half-maximal ([S] = 0.5 Vmax)
What is Km roughly a measure of?
The inverse measure of the affinity or strength of binding between the enzyme and its substrate
What units is Km measured in?
mol l-1
What does a low Km indicate?
A greater affinity for substrate to bind to enzyme - needs little substrate to work at half maximal velocity
Why are hyperbolic graphs not a good way of measuring Km and Vmax?
as they are not linear, reaction velocity will never quite reach true Vmax!!
What is the most widely used and most precise method of linearising the data of the equation?
Lineweaver-Burk plot
What does a high Km indicate?
Low affinity for substrate to bind to enzyme - enzyme needs a lot of substrate to work at half maximal velocity
What is the Michaelis-Menten Equation?
V0 = Vmax [S] / Km + [S]
