Adenine and guanine, the two most common purines in DNA and RNA, share this core structure, which is crucial for forming the base pairs in nucleic acids. (Image: Wikimedia Commons, Public Domain) ...

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?

In other words, the total amount of purines ... bases now fit together perfectly (i.e., A with T and C with G), with each pair held together by hydrogen bonds, but the structure also reflected ...

Chemical structure of guanine, showing its double-ring purine structure and the functional groups involved ... its ability to form three hydrogen bonds with cytosine. This strong base pairing is ...