Suppose that the data shown in the margin are obtained for an enzyme -catalyzed reaction. [S] (mM) V (mmol/ml min) 0.1 3.33 0.2 5.0 0.5 7.14 0.8 8.00 1.0 8.33 2.0 9.09 a.) Determine the Km and Vmax b.) Assuming htat the enzyme present in the system had a concentration of 10-6M, calculate the turn -over number

Calculate the slope on a Lineweaver-Burk plot (Km / Vmax) for the above enzyme (lactase). (enzyme lactase has a Vo of 0.111111111111 mM per minute when [S] = 1.0 mM, and a Vo of 0.20 mM per minute when [S] = 5.0 mM) 0.125 per minute 0.25 per minute 0.50 per minute 1.25 per minute 5.0 per minute

Calculate the Km of the enzyme with these parameters.  kcat = 130s^-1 Vo = 3.0 μMs-1 S = 10 μM Et = 0.09 µM

Acetazolamide is a drug which inhibits carbonic anhydrase. Carbonic anhydrase participates in regulation of the pH and bicarbonate content of a number of body fluids. Figure 2 shows the experimental curve of initial reaction velocity (as percentage of Vma) versus [S] (concentration) for the carbonic anhydrase reaction. The graph also shows the curve in the presence of acetazolamide. 100 No inhibitor 50 Acetazolamide 0.2 0.4 0.6 0.8 [S] (mM) Figure 2 (i) Compare the maximal velocities and Michaelis Menten constants of the enzyme in the absence and the presence of the inhibitor acetazolamide. Determine the nature of inhibition by acetazolamide. Explain your answer. (ii) Name TWO (2) other types of inhibitions besides the inhibition shown by acetazolamide. Sketch a graph of V versus [S] showing curves in the absence of an inhibitor and in the presence of the types of inhibitors not shown by acetazolamide. ("AJO %) A

Your current Vmax (4x10-3 A/S) from the Michaelis-Menten plot has the units of  A/s and was determined using 0.1 mg of ADH in a total volume of 1.25 mL. Use the Beer-Lambert equation followed by simple conversion to express your estimated Vmax in (mol )/s per 1 mg ADH. The molar absorptivity of NADH at 340 nm is 6220 L/(mol*cm).

A particular reaction has a ΔG‡ of 30.0 kJ mol-1 at 25.0 °C. In the presence of an enzyme, the same reaction has a ΔG‡ of 1.50 kJ mol-1 at the same temperature. Calculate the rate enhancement of this enzyme. (R = 8.3145 J mol-1 K-1)

An enzyme-catalyzed reaction has a KM of 20.0 mmol L-1 and Vmax of 17.0 pmol s-1. When a mixed inhibitor is added, the apparent KM is 50.0 mmol L-1 and the apparent Vmax is 5.20 pmol s-1. Calculate α.

Using the appropriate graph and table above, explain what the R48C mutation appears to be doing to the enzyme’s function.  Discuss the kinetic parameter changes and their meaning in this context, not the structure of the enzyme, which was not given to you.

For an enzyme following Michaelis-Menten kinetics, the following Vo vs. S data were obtained in steady state experiments using 2 micromolar enzyme for all measurements: [S] Vo 1 mM 4.0 mM/min 2 mM 4.8 mM/min 4 mM 4.9 mm/min 8 mM 4.95 mM/min Estimate the value of kcat for the reaction. Be sure to include the appropriate units.

The following data were obtained in a study of an enzyme known to follow Michaelis-Menten kinetics: Vo (micromol/min) Substrate added (mM) 200 1.0 400 2.0 800 4.0 1600 8.0 3200 16.0 The enzyme concentration used in all reactions is 106 M. Which of the following is true: O A) The Km for the reaction must be less than 1 mM ○ B) It is possible to determine Km for the reaction, but not Vmax or kcat OC) It is possible to determine only kcat, not Vmax or Km D) It is not possible to determine Vmax for the reaction OE) The ratio Vmax/Km for the reaction cannot be determined