Restriction Enzymes Enzymes that CUT DNA at a specific nucleotide sequence May produce blunt ends or sticky ends. Sequence cut is a palindrome - same letters forward and backwards!

Blunt End Cuts Used to isolate a fragment of DNA Used to cut DNA into pieces for DNA fingerprinting

Sticky End Cuts Used when one DNA fragment is combined with another DNA fragment to make RECOMBINANT DNA Allow complementary base pairs to join together.

Where do Restriction Enzymes come from? Found in bacteria Enzymes are used to cut and degrade viruses that enter their cells Named for species in which R.E. was found Example: EcoR1 was first R.E. to be isolated from E. coli Picture of the protein molecule Sequence of bases cut by EcoR1

Practical Applications Gene for human insulin or human growth hormone placed into a bacterial plasmid. Gene for disease resistance placed into DNA in cells of a corn plant

What’s next? We will use this information to model the genetic engineering of the hormone, insulin You will choose the best restriction enzyme to cut out the insulin gene and place it into the bacterial plasmid