Learn / Metabolism
Metabolic pathways
Every FMK pathway as a clickable map. Pick one pathway to hammer it — next step, enzyme, regulator, cofactor, and the facts that get tested (NADPH and who needs it, rate-limiting steps, deficiencies) — or set it to all pathways for a mixed drill. Every answer says which enzyme and which pathway.
Purine synthesis & salvage
GMP
Made from IMP by IMP dehydrogenase → GMP synthase
IMP dehydrogenase → GMP synthase — Purine synthesis & salvage
Cofactors: NAD⁺, Glutamine, ATP → AMP
Inhibited by: GMP (feedback on its own branch); Mycophenolic acid (IMP dehydrogenase)
ATP is required to make GMP. Mycophenolic acid blocks IMP dehydrogenase — lymphocytes depend on de novo GMP, so it is an immunosuppressant for transplant rejection.
Condition cards:Mycophenolic acid (mycophenolate) →
Made from Guanine (salvage) by HGPRT
HGPRT — Purine synthesis & salvage
Cofactors: PRPP → PPi
Becomes ADP / GDP (NDP) via Base-specific NMP kinase (guanylate kinase)
Base-specific NMP kinase (guanylate kinase) — Purine synthesis & salvage
Cofactors: ATP