what is restriction enzyme ? how does it work?
Restriction enzyme: An enzyme from bacteria that can recognize specific base sequences in DNA and cut the DNA at that site (the restriction site). A restriction enzyme acts as a biochemical scissors. Also called a restriction endonuclease. A restriction enzyme is a protein produced by bacteria that cleaves DNA at specific sites. Bacteria use restriction enzymes to defend against bacterial viruses called bacteriophages (or phage). When a phage infects a bacteria, it inserts its DNA into the bacteria so that it might be replicated.