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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.

Pathway

HMP shunt (pentose phosphate pathway) · Cytosol — liver, adrenal cortex, gonads, lactating mammary gland, adipose, RBCs. Enzymes sit beside the arrows; a ★ marks the rate-limiting step. The map scrolls inside its panel.

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HMP shunt (pentose phosphate pathway)

6-Phosphogluconolactone

Made from Glucose-6-phosphate by Glucose-6-phosphate dehydrogenase (G6PD) ★

Glucose-6-phosphate dehydrogenase (G6PD) ★ rate-limiting · irreversible — HMP shunt (pentose phosphate pathway)

Cofactors: NADP⁺ → NADPH

Activated by: NADP⁺ (oxidative stress lowers NADPH/NADP⁺); Insulin (↑ expression)

Inhibited by: NADPH (product inhibition — high NADPH/NADP⁺ ratio)

Deficiency: G6PD deficiency — X-linked, most common enzyme deficiency worldwide; episodic hemolysis with oxidant stress (infection, fava beans, sulfa/primaquine/dapsone/nitrofurantoin), Heinz bodies & bite cells, neonatal jaundice; malaria-protective

Committed, rate-limiting step; first NADPH. RBCs have no other NADPH source.

Condition cards:G6PD deficiency (incl. favism) →

Becomes 6-Phosphogluconate via 6-Phosphogluconolactonase

6-Phosphogluconolactonase — HMP shunt (pentose phosphate pathway)