JCE Online Journal of Chemical EducationDivision of Chemical Education, American Chemical SocietyAmerican Chemical Society
 | Subscriptions  | Software Orders  | Support  | Contributors  | Advertisers  | 

JCE Print
   Current Issue
 Previous Issues
 Supplements
 Search JCE Index

JCE Digital Library
   ChemInfo
 DigiDemos
 Featured Molecules
 LivTexts
 LrnCom
 QBank
 SymMath
 WebWare

JCE Software
   Latest Releases
 Software & Video
 Downloads
 Support

Only@JCE Online
   JCE Online Store
 JCE HS CLIC
 JCE Discussion Forums
   Biographical Snapshots
 ChemEd Resource Shelf
 Featured Molecules
 Hal's Picks
 Project Chemlab
 Reviewed WWW Sites
 "Web-Ed" Articles

About JCE
   Features
 Publications
 Operations
 Outreach
 Contact Us


  Home > JCE Print > Journal of Chemical Education > Issues > 1999  > May  >
In the Laboratory
The o-Phenylenediamine-Horseradish Peroxidase System: Enzyme Kinetics in the General Chemistry Laboratory
T. M. Hamilton, A. A. Dobie-Galuska, and S. M. Wietstock
Department of Chemistry, Indiana University, Bloomington, IN 47405
Cover
May 1999
Vol. 76 No. 5
p. 642
Abstract
We have developed an enzyme kinetics laboratory experiment that can easily be incorporated into an undergraduate chemistry program. The purpose of the experiment is to measure the kinetic parameters in the oxidative coupling reaction of o-phenylenediamine (OPD) to 2,3-diaminophenazine (DAP), a reaction catalyzed by the enzyme horseradish peroxidase (HRP). Horseradish peroxidase is a protein with a mass of 34 kDa found in the root of the horseradish plant. Students follow the kinetics of the reaction by monitoring the change in intensity of the colored product at 450 nm. Several kinetic runs are performed with varying OPD concentration and fixed HRP concentration and the kinetic parameters are determined by straight-line plots of the Michaelis-Menten equation. Vernier Software Colorimeters interfaced to personal computers via the LabVIEW programming language were used in the experiments. Alternatively, conventional UV-vis spectrophotometers linked to strip-chart recorders could be used for measuring the kinetic runs. The following ranges of values for kinetic parameters were obtained: vmax = 6.5 ± 1.5 x 10-3 mM s-1, KM = 0.6 ± 0.2 mM, k0 = 1.15 ± 0.15 x 103 s-1. Variations including the effects of HRP concentration and inhibitors on the kinetics are discussed.
Supplement
A program (enzyme.exe) is available as supplementary material. In order to use this executable, you must have a National Instruments PC card and the associated NI-DAQ software. The program has been compressed to a sit file (for Macintosh) and a zip file (for Windows).
*  Contents
*  Download
supp642.zip

supp642.sit
More Information
*  Citation
 Hamilton, Todd M.; Dobie-Galuska, A. A.; Wietstock, S. M. J. Chem. Educ. 1999 76 642.
*  Keywords
 Laboratory Instruction; Enzymes; Kinetics; Laboratory Computing / Interfacing; UV-Vis Spectroscopy
*  History
 Created:
Last Updated:		 June 11, 1999
November 22, 2005
<< Previous Article Table of Contents Next Article >>
  Home > JCE Print > Journal of Chemical Education > Issues > 1999  > May  > Page 642


Subscriptions
 Subscription Info
 Order Forms

JCE HS CLIC

Our Secondary School editors work hard to distill all the JCE materials to produce a fraction of particular interest to high school teachers. We call it CLIC.
 JCE HS CLIC

Contributions Welcome
JCE welcomes your submission
 Contributors' Corner

Advertisers
In recent years we have worked hard to better match our advertisers with our readers. When shopping for chemistry education materials, visit our advertisers' WWW sites first.
 Recent Advertisers

Be An Ambassador
Take JCE along on your outreach missions. Copies of the Journal, guest access to JCE Online, our publications catalog, and more are available for your participants.
 Outreach with JCE

Comments to
jceonline@chem.wisc.edu		 Copyright © Division of Chemical Education, Inc., American Chemical Society.
All rights reserved.