Question

Lactose operon produces enzymes:
A. beta-galactosidase, permease and glycogen synthase.
B. beta-galactosidase, permease and transacetylase
C. Permease, glycogen synthase and transacetylase.
D. beta-galactosidase, permease and phosphoglucose isomerase.

Answer 1

Hint: An operon, in more precise terms, is a section of DNA that houses contiguous structural, operator, and regulatory genes. Thus, a functional unit of transcription and genetic control is an operon.

Complete step by step solution:
Operons are DNA segments made up of a collection of linked genes. They are made up of several linked genes, an operator, and a promoter region. - Operons are present in prokaryotes, which include bacteria and archaea, but are absent in eukaryotes.
The lac operon is a single-promoter operon, or collection of genes (transcribed as a single mRNA). The operon's genes produce proteins that enable the bacterium to utilize lactose as a fuel source. Several other enteric bacteria, including E. coli, contain the lac, or lactose, operon. The genes in this operon produce proteins that are responsible for bringing lactose into the cytosol and breaking it down into glucose.
The regulator gene R creates a repressor protein that binds to the operator site and stops structural genes from being transcribed when inducer lactose is absent, which is the mechanism behind the lac operon.
Lactose, an inducer, attaches to the repressor when it is added to the medium, preventing it from binding to the operator. Both mechanisms can be seen in the lac operon. It is a negative control system because the lac repressor, an active repressor that prevents transcription, usually prevents expression. The lac repressor interacts with the operator region to bind and inhibit transcription.
So, option (B) is correct.

Note:
Operons are groups of genes that are managed collectively. François Jacob and Jaques Monod first introduced the operon paradigm for regulating bacterial genes using the negatively regulated lactose genes of E. coli as an example.