Now, notice that the bonding takes place between the third carbon of one sugar and the fifth carbon of the second sugar. And that's exactly why this is called a three to five bond. So this is our phosphol diester bond. So notice that because there are four different types of nitrogenous bases, that means there are four different types of nucleotides. And it is very common to call our nucleotide by the type of nitrogenous base that it contains. So for example, because this nucleotide contains the guanine nitrogenous base, we simply call the nucleotide the guanine.