Problem Set 3: Enzyme Kinetics

General Instructions

1. This is a group activity. 
2. Answer the problems shown below use the previously given pKa table as reference.
3. Submit your answers in pdf/jpg formats only following the naming, Chem40_PS3_<Section>_<Group No.>
4. Only one submission per group is needed. 

Problems

1. 1. According to the Michaelis-Menten equation, what is the v/Vmax ratio when [S] = 4 Km?
   2. If Vmax = 100umol/ml-sec and Km = 2mM, what is the velocity of the reaction when [S] = 20mM?
   3. For a Michaelis-Menten reaction, k₁= 7x10⁷/M-sec, k_-1 = 1x10³/sec and k₂= 2 x 10⁴/sec. What is the value of Km?
   4. The following kinetic data were obtained for an enzyme in the absence of any inhibitor (1), and in the presence of two different inhibitors (2) and (3) at 5mM concentrations. Assume [E]_T is the same in each experiment. (learn how to use the linear reg function in your sci-cals).

a. Determine Vmax and Km for the enzyme. (Hint: Use the Lineweaver-Burk plot).

b. Determine the type of inhibition and the K_I for each inhibitor.

c. Which is the most effective inhibitor. (Hint: the lower the K_I, the more effective the inhibitor. K_I = minimum [I] required to slow down reaction.)