MY CART (5)

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

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping
Menu
Grade:
        I need a note on regulation of gene expression in prokaryotes.
10 months ago

Answers : (1)

Simran Vinaik
askIITians Faculty
1026 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
10 months ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies

Get Extra Rs. 1,590 off

COUPON CODE: SELF10


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


Get Extra Rs. 127 off

COUPON CODE: SELF10

Ask Experts

Have any Question? Ask Experts

Post Question

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