Question

In: Biology

Explain how gene regulation occurs using the lac operon as an example.

Explain how gene regulation occurs using the lac operon as an example.

Solutions

Expert Solution

The process of turning genes on and off is known as gene regulation. These proteins bind to regulatory regions of a gene and increase or decrease the level of transcription. By controlling the level of transcription, this process can determine the amount of protein product that is made by a gene at any given time.

The lactose operon is an operon required for the transport and metabolism of lactose in E.coli and many other enteric bacteria. This operon contains genes coding for proteins in change of transporting lactose into the cystol and digesting it into glucose. This glucose is then used to make energy.

The activity of the promoter that controls the expression of the lac operon is regulated by two different proteins. One of the protein prevents the RNA polymerase from transcribing, the other enhances the binding of RNA polymerase to the promoter.

A repressor protein binds the operator (control) region upstream of the operon preventing transcription. When lactose is present outside the cell, it crosses the cell membrane and acts as an inducer of the operon.CAP promotes RNA polymerase transcription of genes leading to an increase of lac operon expression.

The regulatory gene lacl produces an mRNA that produces a Lac repressor protein, which can bind to the operator of the lac operon.


Related Solutions

Explain how gene regulation occurs using the lac operon as an example
Explain how gene regulation occurs using the lac operon as an example
27. Be able to describe regulation of gene expression in prokaryotes (transcriptional, like the Lac Operon)...
27. Be able to describe regulation of gene expression in prokaryotes (transcriptional, like the Lac Operon) and in eukaryotes (transcriptional and epigenetic regulation).
Explain what are gene regulatory operons,with lac operon and tryptophan operon examples by drawing figures for...
Explain what are gene regulatory operons,with lac operon and tryptophan operon examples by drawing figures for each?
The lac operon is regulated via positive and negative regulation. Explain how each mechanism works on...
The lac operon is regulated via positive and negative regulation. Explain how each mechanism works on this operon, and under which circumstances will the operon be turned on. Include the definition of an operon 2. What are the advantages to a microbe of having inducible enzymes? What is the function of toluene in the experiment where you induced enzyme function?
Predict the level of gene expression of the lac operon, as well as the status of...
Predict the level of gene expression of the lac operon, as well as the status of the lac repressor and the CAP protein, when bacterial growth media contains the following sugars: a) no lactose or glucose, b) lactose but no glucose, c) glucose but no lactose, d) both lactose and glucose.
Describe the likely effect on gene expression of a mutation in the lac operon: a) that...
Describe the likely effect on gene expression of a mutation in the lac operon: a) that delegate the operator b) that mutates the lacI gene inactivating the repressor c) that the promoter mutates in the -10 region
What is the role of lac repressor molecule in bacterial gene regulation? Explain. Explain the term...
What is the role of lac repressor molecule in bacterial gene regulation? Explain. Explain the term disruptive selection in evolution giving a suitable example. What are sister chromatids? Which protein hold them together during cell division? What is the phenomenon of nondisjunction? What are the functions of topoisomerases and DNA polymerases in DNA replication? What are photosystems ? Where exactly the splitting of water and generation of oxygen occur during light dependent reaction of photosynthesis?
Explain how the lac operon is subject to positive and negative control.
Explain how the lac operon is subject to positive and negative control.
Explain how the lac operon is subject to positive and negative control.
Explain how the lac operon is subject to positive and negative control.
The lac operon is just one specific example of an operon that is regulated both negatively,...
The lac operon is just one specific example of an operon that is regulated both negatively, by binding of a repressor, and positively by catabolite repression.  Describe another example of this type, providing details of the ligands that positively and negatively regulate transcription of the operon, and briefly describe the genes in the operon and the molecular logic of the specific operon you describe.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT