Practical #3 - DNA Structure and Function

Question 1

What are restriction enzymes?

Answer 1

• Restriction enzymes are bacterial enzymes that recognize a specific DNA sequence wherever it occurs in the DNA,
• Then they cut the DNA at or near that sequence
  
  • recognition site

Question 2

Why do bacteria use Restirction enzymes?

Answer 2

• to help recognize and destroy foreign DNA

Question 3

What is one mechanism used by bacteria to protets its own DNA?

Answer 3

• By adding a methyl groups to nucleotides of the bacteria’s DNA that could be recognized by the restriction enzyme
  
  • methylation
• this protects the bacteria’s own DNA from hydrolysis

Question 4

Recombinant DNA

Answer 4

• Foreign piece of DNA may thus be incorporated into the DNA