Online Tutorial

Introduction to Enzyme Kinetics: Assay of β-galactosidase (Online Tutorial)

Joanne Kivela Tillotson*

Purchase College, State University of New York


This tutorial is series of Web files that will run in a Web browser. To run the tutorial from your own computer or to load on your own Web site, download the zip file, unzip all the files into a single folder, then open the page called "enzyme_0.html" to start the tutorial. The tutorial relies on scripts, so you must allow scripts or ActiveX controls if prompted by your Web browser. The tutorial includes 11 figures, of which 7 are dynamic or part of assessing student understanding, and 2 tables. If the animated graphs or the assessment questions do not function, it is likely that the scripts are deactivated for the Web browser.

The tutorial provides an overview of enzyme kinetics and describes a colorimetric assay for b-galactosidase activity to illustrate simply enzyme kinetics. Use the "Next" buttons to navigate through the tutorial. Where asked, questions must be answered in order to proceed to the next section. The tutorial begins with "lecture" material that explains and illustrates the concepts. In these text sections, important terms are highlighted in bold.

[Run Tutorial at STKE]

[Click to Download a Zipped Version]

[Run Tutorial from Purchase College State University of New York]

Educational Details

Learning Resource Type: Tutorial: On-line tool; assignment/activity

Context: Undergraduate lower division, undergraduate upper division

Intended Users: Teacher, learner

Intended Educational Use: Learn, Plan, Teach

Discipline: Biochemistry, Biotechnology, Education, Enzymology

Keywords: Tutorial, enzyme assay, kinetics, b-galactosidase, spectrophotometer

Technical Details

Format: Web site constructed of html, Flash, and PDF files

Size: 2.0 MB (Zip file)

Requirements: Flash reader, web browser with Active X controls allowed, such as Internet explorer 6.0 or higher

Limits for Use

Cost: Free

Rights: This material may be downloaded for noncommercial, course-teaching purposes only, provided credit to STKE is included by listing the citation for the Teaching Resource.

*Contact information. E-mail: joanne.tillotson{at}

Citation: J. K. Tillotson, Introduction to Enzyme Kinetics: Assay of beta-Galactosidase. Sci. STKE 2007, tr4 (2007).