Structure of dna Adenine(A) Guanine(G) Cytosine(C) Thymine(T) NH 2 NH N CH HN HN N NH HN N NH O NH O/NHAdenine(A) N N NH N NH2 Guanine(G) N HN NH N H2 N O Cytosine(C) N NH NH2 O Thymine(T) NH HN O O CH3 Structure of DNA