Question

What Is the Lac Z Gene?

Answer 1

Lac Operon:

1. The lac operon is an operon responsible for the transport and metabolism of lactose in Escherichia coli and other bacteria.
2. It carries the genes that code for enzymes involved in lactose metabolism only.
3. The lac operon has three structural genes namely the Lac Z gene, Lac Y gene, And Lac A gene.
4. The lac Z gene codes for β-galactosidase, the main enzyme of the lac operon as it catalyzes the hydrolysis of lactose by converting lactose into glucose and galactose.
5. The lac Y gene codes for β-galactoside permease which transports lactose into the cell.
6. The lac A gene codes for β-galactoside transacetylase which assists the enzyme beta-galactosidase.
7. In the lac operon, lactose acts as an inducer. If lactose is provided in the medium for the bacteria, the regulatory gene is activated. The inducer will bind to the repressor protein and render it inactive which allows transcription of the operon.
8. Thus, the lac operon is negatively regulated in this case.