This image illustrates the chemical structure of a purine molecule, highlighting the numbering of the carbon and nitrogen atoms. The purine structure consists of a pyrimidine ring (positions 1 to 6) ...

The pyrimidines, thymine (DNA), uracil (RNA), and cytosine are shown on top while the purines, adenine and guanine, are shown at the bottom. (Image: adapted from Wikimedia Commons, public domain) The ...

The double helical structure is made of two strands consisting of deoxyribose and phosphate and is held together by bonds between purine and pyrimidine bases which project inward from two chains and ...