The operon model describes how bacteria control the production of groups of enzymes. In this model, synthesis of the messenger RNA coding for these enzymes is switched on or off by regulatory proteins. True or false?

True

Explanation:

The operon model describes the regulatory genes of the operon codes for proteins. These are called regulatory protein that controls the expression of the structural genes of the operon. For example, the gene "I" of the lac operon codes for a regulatory protein called repressor protein.

The repressor protein binds to the sequence that is present in close vicinity of the promoter sequence. This is called the operator sequence. When the repressor protein is bound to the operator, RNA polymerase cannot transcribe the genes of the lac operon.

On the other hand, the presence of an inducer inactivates the repressor and makes it unable to bind to the operator. This allows the expression of the operon.