Answer:
purine
Step-by-step explanation:
Purines are nitrogenous base that have two carbon-nitrogen rings. The most naturally occurring purines are adenine and guanine which are found in DNA and RNA as nucleotide building blocks of these polymers. Purines are constituents other important biomolecules, such as ATP, GTP, cyclic AMP, NADH, and coenzyme A. Purine and pyrimidine ribonucleotides built up essential intermediates in the synthesis of the polynucleotides RNA and DNA.