Enzyme Kinetics MCAT Practice Question
A 45-year-old man with a family history of familial hypercholesterolemia is enrolled in a study examining HMG-CoA reductase enzyme kinetics. Researchers obtain a Lineweaver-Burk plot from hepatic tissue samples to characterize the enzyme's kinetic parameters. The double-reciprocal plot yields a y-intercept of 0.5 min/μmol and an x-intercept of -0.1 mL/μmol. The substrate concentration during the assay is maintained well below the enzyme's saturation point. Which of the following correctly describes the Vmax and Km values calculated from these Lineweaver-Burk coordinates?
Answer choices
- AVmax = 2 μmol/min and Km = 10 mLCorrect answer
- BVmax = 0.5 μmol/min and Km = 0.1 mL
- CVmax = 10 μmol/min and Km = 2 mL
- DVmax = 0.1 μmol/min and Km = 5 mL
- EVmax = 5 μmol/min and Km = 0.5 mL
- FVmax = 0.2 μmol/min and Km = 20 mL
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