Final answer:
An operon is a region of DNA consisting of genes, a promoter, and an operator that regulates transcription. A regulon is a collection of operons controlled by a common regulatory protein. They allow for coordinated gene expression in prokaryotes.
Step-by-step explanation:
An operon is a region of DNA that consists of one or more genes that encode the proteins needed for a specific function. It also includes a promoter and an operator, which help regulate transcription of the operon genes. Operons are found in prokaryotes and are involved in the coordinated regulation of genes.
A regulon, on the other hand, is a collection of operons that are controlled by a common regulatory protein. This means that multiple operons can be turned on or off simultaneously by the same regulatory protein, allowing for coordinated gene expression.
For example, the lac operon in E. coli is part of a regulon that is controlled by the LacI repressor protein. The LacI protein binds to the operator of the lac operon and prevents transcription of the genes involved in lactose metabolism. However, when lactose is present, it binds to the LacI protein and changes its shape, allowing transcription of the genes.