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)
UDP-galactose
Made from Galactose-1-phosphate by Galactose-1-phosphate uridyltransferase (GALT) ★
Galactose-1-phosphate uridyltransferase (GALT) ★ rate-limiting — Galactose metabolism (Leloir pathway)
Deficiency: Classic galactosemia — Gal-1-P is toxic to liver, brain, kidney and lens: vomiting, jaundice, hepatomegaly, failure to thrive days after milk starts; E. coli sepsis; cataracts; intellectual disability. Remove ALL galactose/lactose
Gal-1-P + UDP-glucose → UDP-galactose + glucose-1-P. The critical step.
Condition cards:Galactosemia (GALT deficiency) →
Made from UDP-glucose by GALT (UDP-glucose donates the UDP)
GALT (UDP-glucose donates the UDP) — Galactose metabolism (Leloir pathway)
Becomes UDP-glucose via UDP-galactose 4-epimerase
UDP-galactose 4-epimerase — Galactose metabolism (Leloir pathway)
Reversible — also makes UDP-galactose for lactose, glycoproteins and glycolipids when there is no dietary galactose.