Question

1. How do prokaryotes conserve energy? 2. How do DNA-binding proteins in prokaryotes regulate genes? 3. What is an operon? 4. What is in the lac operon in E. coli? 5. What is the function of the genes in the lac operon of E. coli? 6. What turns the lac operon off? 7. How does a repressor protein turn off the lac operon? 8. How does lactose turn on the lac operon?

Answer 1

Answer1:

Prokaryotes are able to conserve their energy by only producing or regulating the activities ofthose genes which are really important for the survival and function of the cell. They dont waste their energy in producing unnecessary proteins by regulating their gene expression.

Answer 2:

Incase of prokaryotes, the DNA binding proteins regulate the expression of genes by binding Leading to turning on and off of the expression of genes. These small protein molecules are responsible for the switching on of a gene or turning it off hence controlling gene expression.

Answer 3:

Operon may be defined as a group of genes which are related in function and having a promotor and an operator. These are known to be found in prokaryotes and are absent in eukaryotes.  Operons are present in prokaryotes (bacteria and archaea), but are absent in eukaryotes.

Answer 4: Lac or lactose operon contains three genes which are as follows :

lacZ, lacY, and lacA.

Lac operon or lactose operon Which is necessary for the transport and metabolism of lactose certain prokaryotes.

Answer 5 : lac or lactose operon helps the bacteria to use lactose as source of food and in order to utilize it to extract energy by transporting and utilizing by metabolic activities.

Answer6: there is a gene known as repressor gene which produces repressor protein it binds to operator gene and turns the operon off.