And they cleave via the process of hydrolysis phosphodiastor bonds that hold nucleotides together. And these restriction enzymes basically cleave two phosphodiastor bonds in a single double helix DNA molecule and they cleave at specific palindromic sequences. Now, to see what we mean by all that, let's take a look at a specific type of restriction enzyme that is found in E. Coli bacterial cells known as ECoR one. Now, this restriction enzyme basically cleaves at this location and this location along the following palindromic sequence. So notice we have a double stranded DNA molecule. We have one strand, and then we have the complementary lower strand.