Spectroelectrochemical Determination of the Redox Potential of Cytochrome c via Multiple Regression. An Undergraduate Instrumental Analysis or Biochemistry Laboratory Exercise

TCE

The Chemical Educator

ISSN: 1430-4171 (electronic version)

Table of Contents

Abstract Volume 12 Issue 6 (2007) pp 392-395

Spectroelectrochemical Determination of the Redox Potential of Cytochrome c via Multiple Regression. An Undergraduate Instrumental Analysis or Biochemistry Laboratory Exercise

Graham T. Whitaker, Eugene A. Belogay, and Eugene T. Smith*

Harriet L. Wilkes Honors College, Florida Atlantic University, Jupiter, FL 33458, esmith@fau.edu
Received July 1, 2007. Accepted August 10, 2007.

Published online: 18 November 2007

Abstract. This laboratory exercise can be used in an undergraduate course in instrumental methods or biochemistry. Bovine cytochrome c is reduced in the presence of DCIP in an enzyme-coupled redox reaction. The reduction is monitored spectroscopically and the concentrations of the individual species are determined from Beer’s law via multiple regression. The redox potential of cytochrome c is estimated from the Nernst equation via least-squares fit. The purpose of this exercise is to expose students to the hybrid method of spectroelectrochemistry.

Key Words: Laboratories and Demonstrations; general chemistry; biochemistry; quantitative analysis; instrumental analysis

(*) Corresponding author. (E-mail: esmith@fau.edu)

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Supporting Materials:

Instructor notes, a sample student handout, and a sample Excel workbook are available online. The supplements were prepared with Microsoft Word and Excel (2003 SP2). Laboratory instrumentation varies greatly among universities, so the customization of the student handout is left to each instructor. Answers to the sample questions in the student handout are provided at the end of the instructor notes. The Excel workbook contains charts, formulas, and sample data, which are explained in detail in the instructor notes. These materials are available in a Zip file (1.2 MB).