We have a nitrogenous base and we also have our phosphate group. Now, what exactly is the structure or arrangement of these three different types of sections or groups within our nucleotide? So this is one example of a nucleotide. We have our base, the nitrogenous base, attached to our center sugar, which is also attached to our phosphate group. Now, there are four different types of nitrogenous bases. We have adenine, guanine, cytosine and thymine.