Book contents
- Frontmatter
- Contents
- Introduction
- How important is maths in data-handling?
- Abbreviations and the Système International
- Acknowledgements
- 1 Numbers and indices
- 2 A sense of proportion
- 3 Graphs
- 4 Algebra
- 5 Logarithms: exponential and logarithmic functions
- 6 Simple statistics
- 7 Preparing solutions and media
- 8 Enzymes
- 9 Spectrophotometry
- 10 Energy metabolism
- 11 Radioactivity
- 12 Growth in batch cultures
- 13 Growth in continuous culture
- 14 Microbial genetics
- 15 Problems
- 16 Advice and hints
- 17 Answers to problems
- Conclusion
- Further reading
- Index
8 - Enzymes
Published online by Cambridge University Press: 05 June 2012
- Frontmatter
- Contents
- Introduction
- How important is maths in data-handling?
- Abbreviations and the Système International
- Acknowledgements
- 1 Numbers and indices
- 2 A sense of proportion
- 3 Graphs
- 4 Algebra
- 5 Logarithms: exponential and logarithmic functions
- 6 Simple statistics
- 7 Preparing solutions and media
- 8 Enzymes
- 9 Spectrophotometry
- 10 Energy metabolism
- 11 Radioactivity
- 12 Growth in batch cultures
- 13 Growth in continuous culture
- 14 Microbial genetics
- 15 Problems
- 16 Advice and hints
- 17 Answers to problems
- Conclusion
- Further reading
- Index
Summary
Was this the face that launch'd a thousand ships,
And burnt the topless towers of Ilium?
Christopher MarloweAn enzyme is a catalyst produced by a biological process. Very nearly all known enzymes are proteins, but only rarely can one detect an enzyme by identifying the enzymic protein in a mixture. Usually the presence of an enzyme is revealed by showing its catalytic effect on a reaction.
This is done by comparing the rate of the reaction with and without the material that might contain the enzyme. An assay system has to be made which, when complete, will contain: a buffer to give a pH value that is optimal for the enzyme; the substrate of the reaction; any necessary cofactors and activators; and the test material. The mixture without the substrate, or without the test material, is brought to the desired temperature, and then the reaction is started by adding the substrate or test material. There must also be a method to assess the rate of the expected reaction. Such a method could be, for instance, uptake of oxygen; reduction of a cofactor; appearance of the product of the catalysed reaction; release of inorganic phosphate. An observed catalytic effect can be shown to be enzymic by demonstrating that the effect is lost when the presumed enzyme is denatured, as by heat.
- Type
- Chapter
- Information
- Data-Handling in Biomedical Science , pp. 73 - 86Publisher: Cambridge University PressPrint publication year: 2010