5-phosphoribosyl-1-pyrophosphate (PRPP) is a crucial molecule in cellular metabolism. It serves as a ribose phosphate donor in the synthesis of nucleotides, which are the building blocks of DNA and RNA. PRPP is formed from ribose-5-phosphate and ATP through the action of the enzyme PRPP synthetase. In addition to its role in nucleotide synthesis, PRPP is involved in the biosynthesis of certain amino acids and coenzymes. It acts as a substrate for various enzymes, facilitating important biochemical reactions. The regulation of PRPP levels is vital for maintaining cellular functions and overall metabolic balance.