If this base was a puridine when we have only a single ring, then a nitrogen would be nitrogen number one. So the bond always takes place between carbon number one and a nitrogen atom found on our base. Now let's move on to nucleotide. So the only difference between a Nucleotide and a Nucleotide is in Nucleotides, we have the sugar and the base, as well as at least one of the phosphate groups attached to carbon number five on that sugar. Now, sometimes, as we'll see in just a moment, the phosphate group can also be attached to carbon number three. But usually in natural nucleotides found inside our body, we have the phosphate groups attached onto carbon number five.