using restriction endonucleases to isolate DNA fragments

Question 1

define palindromic sequence

Answer 1

reads same backwards as it reads frowards

Question 2

define restriction endonucleases

Answer 2

enzymes that can cut DNA at a specific base sequence

Question 3

what is the base sequence that restriction endonuclease recognise called?

Answer 3

recognition/restriction site

Question 4

where does the restriction endonuclease cut between

Answer 4

two specific bases called the cleavage site

Question 5

define sticky ends

Answer 5

staggered pieces of DNA that are complementary to each other

Question 6

explain what sticky ends are and their importance in recombinant DNA technology

Answer 6

• DNA is cleaved at the recognition site
• restriction endonucleases cuts out the DNA fragment
• staggered cut leaves a sticky end several nucleotide bases long
• any piece of DNA cut with the same restriction endonuclease will have sticky ends that are complentary to each other
• complementary bases of the two sticky ends pair up
• DNA ligase joins sugar phosphate backbone
• allows to bind DNA from one organism to another provided the same restriction endonuclease