
Why is Lactose called an inducer in lac operon?
Answer
422.4k+ views
Hint: The lac operon, or collection of genes with a single promoter, is a kind of operon (transcribed as a single mRNA). The operon's genes code for proteins that allow bacteria to utilise lactose as a source of energy. It is also present in some fungal cells. The three structural genes lac z, lac y and lac a code for three different proteinaceous enzymes which metabolize lactose.
Complete answer:
To solve this question one should know whether lac operon is an inducible or repressible operon.
Lac operon is an example of inducible operon in which an inducer binds to an active repressor making it inactive thus keeping the operon switched ON and the lactose is metabolized.
Lactose binds to the repressor protein and inhibits it from binding to the operator; it serves as an inducer of the lac operon. The repressor attaches to the operator and prevents RNA polymerase from binding to the promoter and starting transcription in the absence of an inducer.
Additional information:
The lac operon, also known as the lactose operon, is present in E. coli and other intestinal bacteria. Genes coding for proteins that transport lactose into the cytosol and breakdown it into glucose are found in this operon. The glucose is subsequently converted into energy.
The lac operon, which contains the structural genes lacZ, lacY, and lacA, encodes the genes required to obtain and digest lactose from the local environment. lacZ codes for β-galactosidase, an intracellular enzyme that breaks down the lactose disaccharide into glucose and galactose. Lactoside permease (lacY) is a membrane-bound transport protein that pumps lactose into the cell. lacA is an enzyme that converts acetyl-CoA to -galactosidase by transferring an acetyl group from acetyl-CoA to -galactosidase.
Note:
Francois Jacob and Jacques Monod devised the operon model of bacterial gene regulation. Operons are units that include groups of genes that code for related proteins. An operon is made up of four genes: an operator, a promoter, a regulator, and a structural gene.
Complete answer:
To solve this question one should know whether lac operon is an inducible or repressible operon.
Lac operon is an example of inducible operon in which an inducer binds to an active repressor making it inactive thus keeping the operon switched ON and the lactose is metabolized.
Lactose binds to the repressor protein and inhibits it from binding to the operator; it serves as an inducer of the lac operon. The repressor attaches to the operator and prevents RNA polymerase from binding to the promoter and starting transcription in the absence of an inducer.
Additional information:
The lac operon, also known as the lactose operon, is present in E. coli and other intestinal bacteria. Genes coding for proteins that transport lactose into the cytosol and breakdown it into glucose are found in this operon. The glucose is subsequently converted into energy.
The lac operon, which contains the structural genes lacZ, lacY, and lacA, encodes the genes required to obtain and digest lactose from the local environment. lacZ codes for β-galactosidase, an intracellular enzyme that breaks down the lactose disaccharide into glucose and galactose. Lactoside permease (lacY) is a membrane-bound transport protein that pumps lactose into the cell. lacA is an enzyme that converts acetyl-CoA to
Note:
Francois Jacob and Jacques Monod devised the operon model of bacterial gene regulation. Operons are units that include groups of genes that code for related proteins. An operon is made up of four genes: an operator, a promoter, a regulator, and a structural gene.
Recently Updated Pages
Master Class 12 Biology: Engaging Questions & Answers for Success

Class 12 Question and Answer - Your Ultimate Solutions Guide

Master Class 12 Business Studies: Engaging Questions & Answers for Success

Master Class 12 Economics: Engaging Questions & Answers for Success

Master Class 12 Social Science: Engaging Questions & Answers for Success

Master Class 12 English: Engaging Questions & Answers for Success

Trending doubts
Father of Indian ecology is a Prof R Misra b GS Puri class 12 biology CBSE

Who is considered as the Father of Ecology in India class 12 biology CBSE

Enzymes with heme as prosthetic group are a Catalase class 12 biology CBSE

A deep narrow valley with steep sides formed as a result class 12 biology CBSE

An example of ex situ conservation is a Sacred grove class 12 biology CBSE

Why is insulin not administered orally to a diabetic class 12 biology CBSE
