10. Applying the Michaelis-Menten Equation II An enzyme catalyzes the reaction M N. The enzyme is present at a concentration of 1 nM, and the Vmax is 2 µM s. The Km for substrate M is 4 µM. (a) Calculate kcat: (b) What values of Vmax and Km would be observed in the presence of sufficient amounts of an uncompetitive inhibitor to generate an a' of 2.0?

10. Applying the Michaelis-Menten Equation II An enzyme catalyzes the reaction M N. The enzyme is present at a concentration of 1 nM, and the Vmax is 2 µM s. The Km for substrate M is 4 µM. (a) Calculate kcat: (b) What values of Vmax and Km would be observed in the presence of sufficient amounts of an uncompetitive inhibitor to generate an a' of 2.0?

Introductory Chemistry: A Foundation

9th Edition

ISBN:9781337399425

Author:Steven S. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Donald J. DeCoste

Chapter21: Biochemistry

Section: Chapter Questions

Problem 28QAP: . Describe the lock-and-key model for enzymes. Why are the shapes of the enzyme and its substrate...

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. Describe the lock-and-key model for enzymes. Why are the shapes of the enzyme and its substrate important in this model? What does it mean to say that an enzyme is inhibited by a particular molecule? What happens if this inhibition is irreversible? Can you think of a situation in which it might be advantageous to be able to inhibit an enzyme?
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Kinetics data were gathered for an enzyme-catalyzed reaction under identical conditions both with and without a noncompetitive inhibitor. When the inhibitor was present at a concentration of 42.2 nM, the value of Vmax decreased by 20.3%. What is the value of Ki for this inhibitor?
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4 1. Use the Michaelis-Menten equation to explain relationship between the amount of product produced and the concentration of enzyme in each reaction. 2. Briefly explain how you would modify the experiment performed in part C to determine the Km and Vmax of the lactase enzyme ANSWER BOTH
Many enzymes are inhibited irreversibly by heavy metal ions such as Hg2+, Cu2+, or Ag+, which can react with essential sulfhydryl groups to form mercaptides:The affinity of Ag + for sulfhydryl groups is so great that Ag+ can be used to titrate —SH groups quantitatively. To 10.0 mL of a solution containing 1.0 mg/mL of a pure enzyme, an investigator added just enough AgNO3 to completely inactivate the enzyme. A total of 0.342 μmol of AgNO3 was required. Calculate the minimum molecular weight of the enzyme. Why does the value obtained in this way give only the minimum molecular weight?
Salicylate (aspirin) inhibits the catalytic action of glutamate dehydrogenase. You measure the activity of this enzyme in the absence and presence of the inhibitor. The data is presented in the table below. Substrate concentration (mM) Micrograms of product per minute, no inhibitor Micrograms of product per minute, 40 mM salicylate 0 0 0 0.5 0.11 0.04 1.5 0.23 0.09 2 0.27 0.1 3 0.32 0.12 4 0.36 0.13 8 0.45 0.16 16 0.5 0.18 In Microsoft Excel, generate the Michaelis-Menten graphs (i.e., the rate versus substrate concentration plots) for each of the inhibitor-free and the inhibitor-containing reactions. Without doing any calculation, and simply by visually observing the plots in Excel, estimate what the Vmax and the Km for this enzymatic reaction in the presence and the absence of the inhibitor. For Vmax, express your answer to one decimal place while using the appropriate rounding. For Km, express your answer to the nearest integer. Enter your answers in the table…
Following data were obtained for an enzyme in the absence and presence of an inhibitor. What are the Km and Vmax values for the inhibited and uninhibited enzymes? What is the type of inhibitor?