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NEETZoologyMolecular Basis of Inheritance

In the lac operon of E. coli, what is the primary biochemical function of the enzyme synthesized by the z gene?

Options

  1. AHydrolysis of the disaccharide lactose into galactose and glucose
  2. BIncreasing the permeability of the cell to -galactosides
  3. CTransferring an acetyl group to -galactosides
  4. DBinding to the operator region to prevent the transcription of structural genes

Correct answer

A. Hydrolysis of the disaccharide lactose into galactose and glucose

Step-by-step solution

In the lac operon, the z gene codes for the enzyme -galactosidase. The primary function of -galactosidase is the hydrolysis of the disaccharide lactose into its monomeric units, galactose and glucose. The other functions listed belong to different gene products: increasing permeability is the role of permease (y gene), transferring an acetyl group is the role of transacetylase (a gene), and binding to the operator is the role of the repressor protein (i gene). Answer: Hydrolysis of the disaccharide lactose into gal

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