Enzyme Lab: A Virtual Lab for Enzyme Kinetics
Jason Brown Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282 Frank R. Gorga Department of Chemical Science, Bridgewater State College, Bridgewater, MA 02325
Note:	This program is included in the Advanced Chemistry Collection (SP-28). To Order Advanced Chemistry Collection
Many biochemistry lab courses include an experiment in enzyme kinetics where students determine the Km and Vmax for an enzymatic reaction. Enzyme Lab presents a virtual lab for performing such an experiment. The main window of Enzyme Lab (see Figure) presents the student with a laboratory bench holding three beakers (with associated pipets), a test tube/cuvette, a vortex mixer, and a spectrophotometer. Enzyme Lab's main window showing beakers containing buffer, enzyme and substrate solutions, the vortex mixer, and spectrophotometer. The beakers contain an enzyme solution (acid phosphatase), substrate solution (p-nitrophenylphosphate), and buffer. The spectrophotometer is modeled after a simple computer-controlled instrument that allows its output to be saved to ASCII files. The student begins an experiment by setting the rate and duration of data collection and zeroing the spectrophotometer. The student then pipets solutions into a test tube, mixes the tube's contents, and places the tube in the spectrophotometer. Data collection begins when the Start button is clicked. The program shows a plot of absorbance vs. time as the data are collected. The student can save the data (time and absorbance) to an ASCII file for detailed analysis using a spreadsheet. The student can then "wash out" the test tube in preparation for another run. Enzyme Lab is designed to give the student wide latitude in performing experiments and to provide a realistic response in almost all cases. For example, if the student forgets to zero the spectrophotometer a random (within limits) absorbance is added to the data. Enzyme Lab is designed as a "data generator" to be used in conjunction with a spreadsheet program for analysis of the data obtained from it (much as a biochemist would work in the real world). Students should import the data (absorbance vs. time) generated by Enzyme Lab into a spreadsheet and determine the rate of each reaction using linear regression. The rates thus obtained can then be analyzed using the Michaelis-Menten model (in any of its forms) to arrive at a Km and Vmax describing the acid phosphatase-catalyzed hydrolysis of p-nitrophenylphos-phate. A help file that reviews basic enzyme kinetics and guides students through the experiment is included. Hardware and Software Requirements   Computer  CPU RAM Drives Graphics Free Disk Space System Software Other  Series D Windows compatible 80386 or higher or Pentium 8 MB Hard disk, 3.5-in. high-density floppy drive 640 x480, 256 colors varies by program Windows 3.1x or Windows 95 --  Enzyme Lab Windows compatible  80386 or higher with math coprocessor 8 MB  Hard disk, 3.5-in. high-density floppy drive 640 x480, 256 colors 2 MB  Windows 3.11 with Win32s or Windows 95  Spreadsheet to complete calculations Lake Study Windows compatible  80386 or higher or Pentium 8 MB  Hard disk, 3.5-in. high-density floppy drive 640 x480, 256 colors  3 MB  Windows 3.1x or Windows 95 --

First Published: July 1997

Citation: Brown, J.; Gorga, F. R. Enzyme Lab: A Virtual Lab for Enzyme Kinetics J. Chem. Educ. Software 5D1

Keywords: Computer Room; Simulation; Analytical; Biochemistry; Enzyme; Reaction rate

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Last Updated: July 19, 2001 Created: June 19, 1997	Created by: Comments to: jceonline@chem.wisc.edu
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