Question

1. What are some benefits and drawbacks to operons?
2. What are the two components of a two-component regulatory system? Describe the localization of these proteins.  What type of covalent modification is utilized in such systems?
3. Attenuation and riboswitches are two methods of controlling gene expression at the level of transcription.  Describe how the process of attenuation occurs in the trp Operon.  How can riboswitches be described as a specialized type of attenuation?
4. What would be the phenotype of an E. colistrain in which the tandem Tryptophan codons in the leader region of the trp operon were mutated so that they are coded or serine instead. Explain.  How is attenuation impacted?

Answer 1

• Operon is a functional unit of transcription and genetic regulation. Operons are cluster of genes that are all under the same control and with related functions.
• Benefit of Operons is that protein synthesis can be controlled according to need of cells.
• Disadvantage:- Any mutation in promotor region of the operon will result in failure of transcription of all genes.

Components of two components regulatory control are membrane bound sensor kinase and DNA bounding response regulator.