Question

Which of the following statements are true of inducible operons?

1) They are regulated by an inducer molecule
2) They are usually turned off by a repressor protein
3) They are involved in catabolic pathways
4) They are always active

Answer 1

Inducible operons are regulated by an inducer molecule and are usually turned off by a repressor protein. They are involved in catabolic pathways and are not always active.

Step-by-step explanation:

Inducible operons are different from constitutive operons in that their expression is regulated by the presence of an inducer molecule that binds to an activator protein and activates transcription. They are typically turned off by a repressor protein that binds to the operator region and prevents RNA polymerase from transcribing the genes. Inducible operons are involved in catabolic pathways, such as the lac operon in E. coli which is involved in lactose metabolism. They are not always active, but their expression is inducible in the presence of the substrate.