<prompt> PRPP Phospho Ribosyl Pyro Phosphate is used in :Purine synthesis Pyrimidine synthesisHistidine synthesisNiacin synthesisAll  <response>: Phosphoribosyl PyrophosphatePRPP is used in the synthesis of : 1. Purine 2. Pyrimidine 3. Histidine 4. Niacin synthesis from Tryptophan. NOTE: Phosphoribosyl pyrophosphate PRPP paicipates in pyrimidine biosynthesis only subsequent to assembly of the pyrimidine ring. PRPP serves as a scaffold for assembly of the purine ring in purine biosynthesis. The first intermediate formed in the de novo pathway for purine biosynthesisis 5-phosphoribosyl 1-pyrophosphate PRPP. 