91Ó°ÊÓ

Organic compounds that are part of DNA and RNA are purines and pyrimidines. The nitrogenous bases of purine are adenine and guanine, and the nitrogenous bases of pyrimidine cytosine and thymine are the backbones of the DNA and RNA structures. The degradation of purines and pyrimidines differs in organisms. purines and pyrimidine nucleotides are precursors in the synthesis of DNA and RNA.

The final product of purine degradation is uric acid in humans and primates. However, in birds and reptiles, the degradation product is the same but does not excrete urea; they catabolize their extra amino acid nitrogen to uric acid via purine biosynthesis.

In humans and primates’ cells degrade pyrimidine nucleotides to their component bases. The degradation of pyrimidine nucleotides occurs via three stages which degrade into β-alanine, carbon dioxide and ammonia.