Where do restriction enzymes come from?
Bacteria use restriction enzymes to cut up viruses at certain sites of their RNA/DNA stand called the restriction sites. This is done in order to stop the virus from replicating itself. This is a protective use for the bacteria.
Researchers then began using restriction enzymes for the purpose of genetic recombination experiments. Insulin, one of the most widely used hormones around the world, is supplied to us thanks to these amazing restriction enzymes and the hard work of bacteria!