PRPP paicipates in purine biosynthesis in _____: (A) Serves as a scaffold for assembly of purine ring, (B) Post assembly of purine ring, (C) Both, (D) None
Answer is A. PRPP serves as a scaffold for assembly of the purine ring in purine biosynthesis. Phosphoribosyl pyrophosphate (PRPP) paicipates in pyrimidine biosynthesis only subsequent to assembly of the pyrimidine ring. Reference: Harpers illustrated biochemistry 30th edition