Difference between Lac and Trp Operon

Lac and Trp Operon are two different processes of sugar and amino acid. Lac works with the catabolic process of sugar whereas Trp Operon works with the anabolic process of amino acid. On a larger scale both processes are involved in special gene alignment in prokaryotes. After alignment, the special function in prokaryotes starts. The organization of gene alignment often allows one gene promoter to activate and at the same time one gene to deactivate. The activation and deactivation process also regulates all the genes. Operon is also called a functional unit of prokaryotic gene expression.


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    Lac works with the catabolic process of sugar and it is the cluster of genes responsible for lactose transportation. It functions in the metabolism of E. Coli bacteria. Unlike Trp Operon, Lac has one promoter region while it has more than one gene compatibility including Lac Z, Lac Y, Lac A and Lac I. It often activated by the presence of lactose. Essentially, the Lac series of genes produce beta galactosidase along with lactose permease and more importantly thiogalactoside transacetylase enzymes. These enzymes also take part and function to allow lactose to come into a cell. It also allows different substances in the cell. This function is an automatic process in the cell that slowly produces a binding protein and gives strength to transcription of allolactose. On the other hand, protein binds travel further into promoter region of lac operon gene transcription.

    - Image Courtesy: en.wikipedia.org

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    Trp Operon

    Trp Operon works with the anabolic process of amino acid and it has single promoter in a cluster of genes. This cluster performs different functions and contains genes for Trp syntheses. An unusual amino acid that is called Tryptophan consists of E, trp D, trp C, trp B, and trp A. Trp Operon is slightly more complex than Lac as it collectively performs different functions in the presence of tryptophan. In Trp Operon, the R trp is basically a repressor and is bound to a promoter region like in Lac. The proteins of this repressor region are released at once from the promoter region as the transcription of the genes start. It is a complex function but at the same time continuously happens in amino acid.

    - Image Courtesy: freewebs.com

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