And that means our bonds can form and those bonds are not disrupted by any type of outside force that is found on the outside of that double stranded DNA molecule. Of course, if we, for example, increase the temperature, eventually a temperature will be reached where these bonds will break, regardless of the fact that our nitrogenous bases are found inside that DNA molecule. So once again, DNA is basically a polymer molecule that contains nucleotides. And any given nucleotide consists of three sections. We have the sugar, the nitrogenous base and our phosphate group. And there are four different types of nitrogenous bases.