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 K_{m}. Use the Michaelis-Menten equation to determine what percentage of the V_{max} will be equal to the value of V _{0}.

B) Now suppose the [S] = 20 K_{m}. Use the Michaelis-Menten equation to determine what percentage of the V_{max} 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 V_{0} vs. [S] plot for a Michaelis-Menten enzyme is false?

Practice: What is the ratio of [S] to K_{m} ( [S] / K_{m }) when the V_{0} of an enzyme-catalyzed reaction is 80% of the V_{max}?

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 K_{m} for this substrate is 1 x 10^{-5} M. Assume that Michaelis-Menten kinetics are followed, calculate the initial reaction velocity (V_{0}) when:

A) [S] = 1 x 10^{-5} M. V_{0} = ___________

B) [S] = 1 x 10^{-2} M. V_{0} = ___________