Question

What is the first complete nucleotide made by the purine de novo pathway?

Answer 1

Purine nucleotide derived from adenine = Adenosine monophosphate (a type of purine nucleoside monophosphate) and liver is the major site for de novo purine synthesis.

First complete nucleotide made by the purine de novo pathway is the Ribose 5-phosphate which gives Inosine Monophosphate (IMP) this purine nucleotide is not named by its base.

Synthesis of purine nucleotides starts with Ribose 5-Phosphate

Step 1: Ribose-5-P→PRPP by PRPP synthase (remember from here, PRPP can go to another pathway to make pyrimidine)

Step 2: PRPP→5-PR-amine by glutamine PRPP amidotransferase

Step 3:5-PR-amine→IMP (9 steps involved which requires glycine, aspartate, THF, CO2, and glutamine)

Step 4: IMP→AMP and GMP

Urine nucleotides are nitrogen-containing compounds made from 6 components→ ribose 5- Phosphate, Aspartate, Glycine, Glutamine, Tetrahydrofolate and CO₂

Purine degradation products, which ends up in uric acid, is associated with  de novo pathway.