The part of a nucleotide molecule in DNA that encodes genetic information is the nitrogenous base. DNA nucleotides consist of three components: a phosphate group, a sugar (deoxyribose), and a nitrogenous base. The nitrogenous bases are adenine (A), thymine (T), cytosine (C), and guanine (G).
These bases pair up in a specific manner—adenine with thymine and cytosine with guanine—to form the rungs of the DNA double helix. The sequence of these bases along the DNA strand encodes the genetic instructions necessary for the development, functioning, and reproduction of all known living organisms.
In summary, the nitrogenous bases in the nucleotide molecules of DNA are responsible for encoding genetic information through their specific sequences and pairings.