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 degradation & uric acid · Cytosol (nucleotidase, PNP, ADA) and liver/gut xanthine oxidase; uric acid excreted by the kidney. Enzymes sit beside the arrows; a ★ marks the rate-limiting step. The map scrolls inside its panel.
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Purine degradation & uric acid
Allantoin (not in humans)
Made from Uric acid (urine) by Urate oxidase (uricase) — ABSENT in humans
Urate oxidase (uricase) — ABSENT in humans — Purine degradation & uric acid
Most mammals make soluble allantoin. Rasburicase is recombinant urate oxidase — first line for tumour lysis syndrome.
Condition cards:Tumor lysis syndrome (TLS) →Rasburicase (recombinant urate oxidase) →