Purine & Pyrimidine: Building Blocks of DNA & RNA

Purine and pyrimidine are two types of nitrogenous bases that are found in DNA and RNA molecules.

Purines are larger molecules that consist of a double-ring structure made up of nitrogen and carbon atoms. The two purine bases found in DNA and RNA are adenine (A) and guanine (G).

Pyrimidines are smaller molecules that consist of a single-ring structure made up of nitrogen and carbon atoms. The three pyrimidine bases found in DNA and RNA are cytosine (C), thymine (T) (only found in DNA), and uracil (U) (only found in RNA).

The sequence of these nitrogenous bases in DNA and RNA molecules determines the genetic information and plays a crucial role in the functioning and expression of genes.