Sections
Enzymes
Enzyme-Substrate Complex
Lock and Key Vs. Induced Fit Models
Optimal Enzyme Conditions
Activation Energy
Types of Enzymes
Cofactor
Catalysis
Electrostatic and Metal Ion Catalysis
Covalent Catalysis
Reaction Rate
Enzyme Kinetics
Rate Constants and Rate Law
Reaction Orders
Rate Constant Units
Initial Velocity
Vmax Enzyme
Km Enzyme
Steady-State Conditions
Michaelis-Menten Assumptions
Michaelis-Menten Equation
Lineweaver-Burk Plot
Michaelis-Menten vs. Lineweaver-Burk Plots
Shifting Lineweaver-Burk Plots
Calculating Vmax
Calculating Km
Kcat
Specificity Constant

Concept #1: Michaelis-Menten Equation:

Example #1: Consider the following enzyme kinetics data for the enzyme catalyzed reaction of A -> B.

Practice: A) Suppose the [S] = 10 Km. Use the Michaelis-Menten equation to determine what percentage of the Vmax will be equal to the value of V 0.

B) Now suppose the [S] = 20 Km. Use the Michaelis-Menten equation to determine what percentage of the Vmax will be equal to the value of V 0. What conclusion can be made from these calculations?

Practice: Which of the following statements about a V0 vs. [S] plot for a Michaelis-Menten enzyme is false?

Practice: What is the ratio of [S] to Km ( [S] / K) when the V0 of an enzyme-catalyzed reaction is 80% of the Vmax?

Practice: An enzyme-catalyzed reaction was carried out with a [substrate] initially 1000 times greater than the Km for that enzyme. After 9 minutes, 1% of the total substrate was converted into 12 μmoles of product. If in a separate experiment, one-third as much enzyme and twice as much substrate had been combined, how long would it take for the same amount of product (12 μmoles) to be formed?

Practice: An enzyme catalyzes a reaction at a velocity of 10 μmol/min when all enzyme active sites are occupied with substrate. The Km for this substrate is 1 x 10-5 M. Assume that Michaelis-Menten kinetics are followed, calculate the initial reaction velocity (V0) when:

A) [S] = 1 x 10-5 M. V0 = ___________ 

B) [S] = 1 x 10-2 M. V0 = ___________