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.
Galactose metabolism (Leloir pathway)
Galactose
Made from Lactose by Lactase (intestinal brush border)
Lactase (intestinal brush border) — Galactose metabolism (Leloir pathway)
Lactose → glucose + galactose. Lactase deficiency = osmotic diarrhea, bloating; not a Leloir defect.
Condition cards:Lactose intolerance (lactase deficiency) →
Becomes Galactose-1-phosphate via Galactokinase
Galactokinase — Galactose metabolism (Leloir pathway)
Cofactors: ATP → ADP
Deficiency: Galactokinase deficiency — galactose & galactitol accumulate: infantile 'oil-droplet' cataracts, no liver or brain disease; reversible with early diet
Condition cards:Galactokinase deficiency →
Becomes Galactitol (lens) via Aldose reductase
Aldose reductase — Galactose metabolism (Leloir pathway)
Cofactors: NADPH → NADP⁺
Galactitol has no exit from lens fibres → osmotic swelling → cataract. Worse in GALT deficiency (higher galactose load).