4. The biosynthesis of AMP and GMP is egulated by feedback inhibition PRPP synthetase and glutamine-PRPP amidotransferase are both inhibited by the end products IMP, AMP and GMP(AMP and GMP act synergistically) AMP inhibits adenylosuccinate synthetase and gMP inhibits ImP dehydrogenase AMP and GMP synthesis is balanced by the following mechanism: GTP is needed for AMP synthesis and atP for GMP synthesis4. The biosynthesis of AMP and GMP is regulated by feedback inhibition PRPP synthetase and glutamine-PRPP amidotransferase are both inhibited by the end products IMP, AMP and GMP (AMP and GMP act synergistically). AMP inhibits adenylosuccinate synthetase and GMP inhibits IMP dehydrogenase. AMP and GMP synthesis is balanced by the following mechanism: GTP is needed for AMP synthesis and ATP for GMP synthesis