What do the nucleic adds you formed have in common? How do adenine and thymine differ? How do uracil and thymine differ? Describe the structure of ATP. How does its structure relate to its function as an energy molecule? Solution 15). In our body, cells contain two nucleic acids namely, DNA (deoxyribonucleic acid) and RNA (ribonucleic acid), which carry the genetic material. Nucleotides are the functional units of these nucleic acids. Nucleotides contain three parts in their structure; one phosphate, nitrogen- containing base (purines and pyrimidines) and a 5-carbon sugar. Nucleotides of DNA contain four nitrogen bases, adenine (A), thymine (T), guanine (G) and cytosine (C). RNA contains uracil (U) in place of thymine (T)..