Use Coupon: CART20 and get 20% off on all online Study Material

Total Price: Rs.

There are no items in this cart.
Continue Shopping
        I need a note on regulation of gene expression in prokaryotes.
2 years ago

Answers : (1)

Simran Vinaik
askIITians Faculty
1231 Points
							E. coli can use either glucose or lactose as the sole source of carbon and energy. When E. coli cells are grown in a glucose-containing medium, the activity of the enzymes needed to metabolize lactose is very low.?

When lactose is absent the Repressor is transcribed and translated from I (regulatory) gene. This repressor goes and binds to operator region and prevents Rna polymerase from transcribing the metabolizing enzymes. At this time gene expression of Lac Operon is shut off.

When these cells are switched to a medium containing lactose but no glucose, the activities of the lactose-metabolizing enzymes increase. The lactose inactivates the repressor and RNA polymerase transcribes 3 genes – lac Z,Y,A in lac operon.
  • The lacY gene encodes lactose permease, pumps lactose inside the cell.
  • The lacZ gene encodes β-galactosidase,which splits the disaccharide lactose into the monosaccharides glucose and galactose.
  • The lacA gene encodes transacetylase.
This is how gene expression is regulated in absence and presence of lactose.
554-2273_lac operon.jpg
2 years ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies

Course Features

  • 728 Video Lectures
  • Revision Notes
  • Previous Year Papers
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Test paper with Video Solution

Course Features

  • 50 Video Lectures
  • Revision Notes
  • Test paper with Video Solution
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Previous Year Exam Questions

Ask Experts

Have any Question? Ask Experts

Post Question

Answer ‘n’ Earn
Attractive Gift
To Win!!! Click Here for details