Using Restriction Enzymes

Question 1

What are restriction enzymes used for?

Answer 1

As well as PCR, another way to get a DNAA fragment from an organisms’ DNA is by using restriction enzymes

Question 2

What are palindromic sequences?

Answer 2

Some sections of DNA have palindromic sequences of nucleotides
These sequences consist of antiparallel base pairs (base pairs read in opposite directions)

Question 3

Describe and explain how restriction enzymes work?

Answer 3

Restriction enzymes recognise specific palindromic sequences (known as recognition sequences) and cut the DNA at these places

Different restriction enzymes cut at different specific recognition sequences, because the shape of the recognition sequences is complementary to an enzyme’s active site

Question 4

How to remove DNA fragment if recognition sequences are present at either site of the DAN fragment?

Answer 4

You can use restriction enzymes to separate it from the rest of the DNA.

The DNA samples is incubated with the specific restriction enzyme, which cuts the DNA fragment via a hydrolysis reaction.
Sometimes the cut leaves sticky ends - small tails of unpaired bases at each end of the fragment

Sticky ends can be used to bind (anneal) the DNA fragment to another a piece of DNA that has sticky ends with complementary sequences