This document discusses nucleotide biosynthesis in cells. It outlines that there are two main pathways for nucleotide synthesis: de novo synthesis and salvage pathways. The de novo synthesis pathway involves the synthesis of purine nucleotides like IMP, which is the precursor for adenine and guanine. It also involves the synthesis of pyrimidine nucleotides like uracil. The salvage pathways allow cells to reuse purine and pyrimidine bases obtained from the breakdown of nucleic acids. The document provides an overview of the key steps in both de novo and salvage synthesis of purine and pyrimidine nucleotides in cells.

1. NUCLEOTIDE BIOSYNTHESIS
Bio-synthesis of Purines & Pyrimidines
BY
VANA JAGAN MOHAN RAO M.S.Pharm., MED.CHEM
NIPER,KOLKATA
Asst.Professor, MIPER-KURNOOL
EMAIL- jaganvana6@gmail.com

2. “The formation of DNA's structure by Watson and Crick may turn out to be the
greatest developments in the field of molecular genetics in recent years”
Linus Pauling, 1953
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3. Learning objectives:
How nucleotides are synthesized in the cells?
Understand the Two Pathways of nucleotide biosynthesis
 (1). De-novo synthesis and (2). Salvage Pathways
De-novo synthesis of purines
 Synthesis of IMP (precursor of adenine and guanine)
 Synthesis of Adenine and Guanine from IMP
De-novo synthesis of pyrimidines
 Synthesis of Uracil
 Synthesis of Cytosine
 Synthesis of deoxy nucleotides
 Synthesis of Thymine Salvage
pathways of Purines and Pyrimidines
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