1. in lac operon; gene activity is induced when lactose is present in the medium, whereas in case of trp operon, repression of the gene activity takes place in presence of tryptophan in the medium.
2. lac operon spans about 4-6kb...whereas trp operon spans abut 7kb.
3. lac operon helps in the breakdown of lactose into glucose and galactose, to generate energy( catabolic pathway ) in case of trp operon, it helps in the synthesis of enzymes required for the formation of the amino acid Tryptophan( anabolic pathway ).
4. lac operon is an example of positive regulation ; and trp operon is an example of negative regulation.
Trp operon is also regulated by other mechanism called attenuation while no such even occurs in lac operon . .
No, the lac operon is not the only example of genes regulated by repressor proteins. There are many other gene regulatory systems where repressor proteins play a role in controlling gene expression. Examples include the trp operon, the ara operon, and the gal operon in bacteria.
repressor gene
One clue that the lac operon is on is the presence of lactose in the environment. The lac operon is induced when lactose is available as a substrate for the lac repressor protein, allowing transcription of genes involved in lactose metabolism.
The lac operon is turned on when lactose is present in the environment and glucose is scarce. This leads to the activation of the lac repressor protein, allowing the expression of genes involved in lactose metabolism. The lac operon is turned off when lactose is absent or glucose is abundant, which prevents the unnecessary expression of these genes.
The lac operon is shut off when lactose is absent. In the absence of lactose, the repressor protein binds to the operator site, preventing transcription of the lac operon genes.
allolactose acts as an inducer
The lac operon and trp operon are both key regulatory mechanisms in bacteria that control gene expression in response to environmental conditions. The lac operon, which is involved in lactose metabolism, is activated in the presence of lactose and inhibited by glucose, functioning primarily through an inducible system. In contrast, the trp operon regulates tryptophan biosynthesis and operates as a repressible system, being turned off when tryptophan levels are sufficient. Thus, while the lac operon responds to the availability of substrates, the trp operon responds to the abundance of end products.
No, the lac operon is not the only example of genes regulated by repressor proteins. There are many other gene regulatory systems where repressor proteins play a role in controlling gene expression. Examples include the trp operon, the ara operon, and the gal operon in bacteria.
its an operon required for the transport and metabolism of lactose.
binding to the trp repressor, causing a conformational change that allows it to bind to the operator region of the trp operon. This blocks RNA polymerase from transcribing the genes, turning off expression of the trp operon.
repressor gene
One clue that the lac operon is on is the presence of lactose in the environment. The lac operon is induced when lactose is available as a substrate for the lac repressor protein, allowing transcription of genes involved in lactose metabolism.
explain the regulation of gene expression in lac operon.
The lac operon is most active when glucose levels are low and lactose is present.
trp operon
The lac operon is turned on when lactose is present in the environment and glucose is scarce. This leads to the activation of the lac repressor protein, allowing the expression of genes involved in lactose metabolism. The lac operon is turned off when lactose is absent or glucose is abundant, which prevents the unnecessary expression of these genes.
The lac operon is shut off when lactose is absent. In the absence of lactose, the repressor protein binds to the operator site, preventing transcription of the lac operon genes.