Nucleic Acid: Large biomolecules composed of nucleotides, which are made up of a nitrogenous base, a sugar, and a phosphate group. Nucleic acids, such as DNA and RNA, store and transmit genetic information.
Purine: A class of nitrogenous bases that are composed of a pyrimidine ring fused to an imidazole ring. Purines include adenine and guanine, which are found in DNA and RNA.
Nucleotide: The basic structural unit of nucleic acids, consisting of a nitrogenous base, a five-carbon sugar, and a phosphate group. Nucleotides are the building blocks of DNA and RNA.