1. A class of organic compounds containing a six-membered aromatic ring with two nitrogen atoms; found as components of nucleic acids (DNA and RNA).
Usage: chemistry; biochemistry; plural form

Examples

• Cytosine, thymine, and uracil are the three main pyrimidines found in nucleic acids.
• Pyrimidines pair with purines to form the base pairs in DNA.
• The structure of pyrimidines differs from that of purines in the number and arrangement of nitrogen atoms.
• Students studying molecular biology must learn to distinguish between pyrimidines and purines.
• Pyrimidines are essential building blocks for the synthesis of RNA and DNA in living cells.