My Learning Cart
?
Categories
Account

What happens when lactose is present in the environment of E. coli?

₹0.0
Login to Download
  • 📥 Instant PDF Download
  • ♾ Lifetime Access
  • 🛡 Secure & Original Content

What’s inside this PDF?

Question: What happens when lactose is present in the environment of E. coli?

Options:

  1. The lac repressor binds to the operator
  2. Transcription of the lac operon is inhibited
  3. The lac repressor is inactivated
  4. cAMP levels decrease

Correct Answer: The lac repressor is inactivated

Solution: 

When lactose is present, it binds to the lac repressor, causing a conformational change that inactivates the repressor and allows transcription of the lac operon.

What happens when lactose is present in the environment of E. coli?

Practice Questions

Q1
What happens when lactose is present in the environment of E. coli?
  1. The lac repressor binds to the operator
  2. Transcription of the lac operon is inhibited
  3. The lac repressor is inactivated
  4. cAMP levels decrease

Questions & Step-by-Step Solutions

What happens when lactose is present in the environment of E. coli?
  • Step 1: Lactose enters the environment where E. coli bacteria are present.
  • Step 2: Lactose molecules bind to a protein called the lac repressor inside the E. coli.
  • Step 3: When lactose binds to the lac repressor, it changes the shape of the repressor (this is called a conformational change).
  • Step 4: The change in shape makes the lac repressor unable to bind to the DNA, which means it cannot block the genes it usually controls.
  • Step 5: With the repressor inactive, the genes of the lac operon can be turned on (transcribed), allowing the bacteria to use lactose as a food source.
  • Lactose and the lac operon – Lactose acts as an inducer that binds to the lac repressor, leading to the activation of the lac operon for transcription.
  • Gene regulation – Understanding how environmental factors like lactose influence gene expression in prokaryotes.
Soulshift Feedback ×

On a scale of 0–10, how likely are you to recommend The Soulshift Academy?

Not likely Very likely
Home Practice Performance eBooks