Understanding Enzyme Kinetics: Practice Questions and
School
University of the Fraser Valley**We aren't endorsed by this school
Course
SOC 190
Subject
Biology
Date
Dec 12, 2024
Pages
2
Uploaded by DrScienceMongoose18
Chapter 6-Enzymes- practice questions 1. An enzyme has a Vmax of 1.2uM/s. The Km for its substrate is 10uM. Calculate the initial velocity of the reaction, V0, when the substrate concentration is: a. 2uM b. 10uM c. 30uM 2. Graphical methods are available for accurate determination of Vmax and km of an enzyme-catalyzed reaction. However, these quantities can sometimes be estimated by inspecting values of V0 at increasing [S]. Estimate the Vmax and Km of the enzyme-catalyzed reaction for which the data in the table were obtained. 3. The enzyme hexokinase catalyzes the phosphorylation of glucose to glucose-6-phopshate as the first step of glycolysis. The initial rate of the reaction was measured as a function of the concentration of glucose. The following data were obtained: [glucose] uM V0(micromoles/min) 0.05 0.06 0.1 0.18 0.5 0.81 1 1.8 5 7.6 10 14 50 41 100 57 500 76 1000 80 5000 81
A. What is the Km of the enzyme for glucose? B. What is the value of V0when [glucose] = 50? C. The above data were plotted as 1/V0versus 1/[glucose], and a straight line was obtained. What is the value of the y-intercept of the line?4. Prostaglandins are one class of the fatty acid derivatives called eicosanoids. Prostaglandins produce fever and inflammation, as well as the pain associated with inflammation. The enzyme prostaglandin endoperoxide synthase, a cyclooxygenase, uses oxygen to convert arachidonic acid to PGG2, the immediate precursor of many different prostaglandins. Ibuprofen inhibits prostaglandin endoperoxide synthase, thereby reducing inflammation and pain. The kinetic data given in the table are for the reaction catalyzed by prostaglandin endoperoxide synthase in the absence and presence of ibuprofen. Based on the data, determine Vmax and the Km of the enzymeand enzyme with inhibitor. Then based on this information, determine the typeof inhibitor (competitive or uncompetitive). 10,000 82 20,000 82