DNA is fundamental to the biology of all life on Earth, but how many of us actually know what it is or what it's made of?

The purine structure consists of a pyrimidine ring (positions 1 to 6) fused to an imidazole ring (positions 7 to 9). Adenine and guanine, the two most common purines in DNA and RNA, share this core ...

This diagram depicts the chemical structure of pyrimidine, a six-membered aromatic ring with two nitrogen atoms at positions 1 and 3 (highlighted in blue). The remaining positions are occupied by ...

Laying the Groundwork: Levene Investigates the Structure of DNA Meanwhile ... In other words, the total amount of purines (A + G) and the total amount of pyrimidines (C + T) are usually nearly ...