Using 5-phosphoribosyl-1-pyrophosphate (PRPP), the de novo pathway enzymes build purine and pyrimidine nucleotides from “scratch” using simple molecules such as CO2, amino acids and tetrahydrofolate.

1. INTERMEDIARY
METABOLISM
PRESENTED BY
Mr.Karthick J.
The Biosynthesis of
Purines
de novo pathway for purine
biosynthesis

5. PURINES AND PYRIMIDINES
Purines &Pyrimidines are two classes of nucleotides in the cells
Primary function of nucleotide is to act as building blocks of DNA and RNA
Purines:Tw o types:Adenine & Guanine
Pyrimidines: Three types: Thymine, Cytosine & Uracil
Apart their role of "genetic information storage", nucleotides also serves
different functions in the cells such as:
Energy carrier (ATP and GTP)
Components of co-enzymes (NAD and FAD)
Signal transduction (CAMP and CGMP as 'second messengers)

6. PURINES AND PYRIMIDINES
Two pathways for the biosynthesis of Nucleotide:
Denovo synthesis: biochemical pathway where nucleotides are
Synthesized new from simple precursor molecules
Salvage pathway: used to recover bases and nucleosides formed during
the degradation of RNA and DNA