whats this anwser?

Question

Descibe how the lac operon functions, and explain how it permits E. coli to produce the enzymes needed to break down lactose when it is present in the bacterium.

Answer 1

The lac operon is a part of the gene that permits bacteria to metabolize lactose. On a gene, there is an operon, a promotor and 3 genes that have to be transcribed in order to produce the protein needed. Promotor regions are high and Adenines and Thymines.
Anyways, an repressor protein binds onto the promotor region when there is a low availability of lactose. This prevents transcription of the gene. When lactose becomes available, the repressor falls off and allows the gene to be transcribed, and the protein will be produced to metabolize/digest lactose.
It is an effective mechanism since bacteria will not be continually using ATP to create this protein, and it is under control at all times. This also differs from the trp operon, which acts as a corepressor--when there is alot of tryptophan, the gene stops being transcribed.

Answer 2

The lac operon is an operon required for the transport and metabolism of lactose in Escherichia coli and some other enteric bacteria. It consists of three adjacent structural genes, a promoter, a terminator, and an operator. The lac operon is regulated by several factors including the availability of glucose and of lactose.

http://web.mit.edu/esgbio/www/pge/lac.html

Go to this web page you can see the detailed description of lactose metabolism system in E. Coli

hope it will help

Answer 3

Go to this link. My fingers would get too tired typing all the answer.

http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/L/LacOperon.html