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The melibiose operon is a group of genes found in Gram Negative Enterobacteria that regulate melibiose degradation as a carbon source.
It consists of three genes, which are all under regulation by two promoters. One promoter is active at high glucose levels, which leads to the transcription of an inhibitor of the rest of the operon. The other promoter is active at low glucose levels that activates expression of the enzymes needed to break down melibiose.
The three genes are melA, melB, and melR. melA encodes the enzyme (alpha-galactosidase) that degrades melibiose into glucose and galactose. melB encodes a permease (pump) that allows melibiose to enter the cell. melR encodes a transcriptional regulator, which is responsible for the regulation of the promoters described above.
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The operon that controls the metabolism of lactose is called the what?
its an operon required for the transport and metabolism of lactose.
Is operon proteins?
Operon is not a protein. It is a segment of DNA that has cluster of genes controlled by the elements such as promoter, operator. Lac operon is a classic example where it regulate the utilization of Lactose in the medium.
Why lac operon the gene expression is switch off?
explain the regulation of gene expression in lac operon.
When a group of gene pairs act together?
A group of genes that is operated together is an Operon.
How many genes in the lac operon are found in e. coli?
My answer is 3, I am pretty sure I am right, but I would double check to make sure. I am in ninth grade taking biology at PineTree.
The operon that controls the metabolism of lactose is called the what?
its an operon required for the transport and metabolism of lactose.
What acts as an on and off switch in an operon?
which part of an operon acts as the on or off switch?
When does the induction of the lac operon occur?
The lac operon is most active when glucose levels are low and lactose is present.
What are the roles of allolactose in the lac operon and tryptophan in trp operon?
allolactose acts as an inducer
What turns the lac operon on and off?
The lac operon is turned off and on by repressors.
How is lac operon different from trp operon?
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 . .
The tryptophan operon is a repressible operon that is?
Turned off whenever tryptophan is added to the growth medium
Is operon proteins?
Operon is not a protein. It is a segment of DNA that has cluster of genes controlled by the elements such as promoter, operator. Lac operon is a classic example where it regulate the utilization of Lactose in the medium.
Why lac operon the gene expression is switch off?
explain the regulation of gene expression in lac operon.
When is lac operon most active?
The lac operon is most active when glucose levels are low and lactose is present.
When a group of gene pairs act together?
A group of genes that is operated together is an Operon.
How many genes in the lac operon are found in e. coli?
My answer is 3, I am pretty sure I am right, but I would double check to make sure. I am in ninth grade taking biology at PineTree.
