Induction of the Lac Operon in E.coli

Produced by Science & Plants for Schools (SAPS), this activity enables students to look at the induction of the lac operon in the bacterium Escherichia coli (E. coli).

Lactose is found in milk but not in many other environments. The enzyme, beta-galactosidase breaks down lactose to glucose and galactose. E.coli switch on the gene for the enzyme, only when it is required. The control mechanism for this process is the lac operon.

During this investigation students look at the beta-galactosidase activity expressed by E. coli grown in media with and without lactose.

The investigation is designed for students following a Scottish Highers course but it is equally useful for other post-16 courses in biology.

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This resource is part of Science & Plants for Schools (SAPS): secondary and post-16 resources