Compare and contrast the de novo synthesis of purine and pyrimidine ribonucleotides. move each item to the appropriate bin. if a phrase does not describe either purine or pyrimidine ribonucleotide synthesis, move it to the \"neither\" bin.
Purines: Heterocyclic rings are synthesized one atom at a time, first atom attached to ribose phosphate (source is PRPP) and then all the other atoms are added .
Pyrimidines: Common intermediate, orotate, synthesized first, then orotate is attached to ribose phosphate (source is PRPP or 5-Phosphoribosyl-1-pyrophosphate).
