METABOLISM OF PURINE NUcLEOTIDES
The purine ring is synthesized de novo in mammalian cells utilizin amino acids as carbon and nitrogen donors, and formate and co2, as carbos donors.
The numbering system for the purine ring is shown in Figure 13.10 with the sources for the various carbon and nitrogen atoms indicated. From the sources of carbon and nitrogen which make up the purine ring it is very evident that amino acids play an important role in nucleotide metabolism.