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.
HMP shunt (pentose phosphate pathway) · Cytosol — liver, adrenal cortex, gonads, lactating mammary gland, adipose, RBCs. Enzymes sit beside the arrows, ★ = rate-limiting, ⊕/⊖ = activators/inhibitors (toggle), −ATP +NADH = what the step spends and makes (toggle ⚡), dashed = allosteric signal, shaded bands = compartment. Drag to pan.
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HMP shunt (pentose phosphate pathway)
Glyceraldehyde-3-phosphate
Made from Ribose-5-phosphate by Transketolase
Transketolase — HMP shunt (pentose phosphate pathway)
Cofactors: TPP (thiamine, B₁)
Transfers 2-carbon units. Reversible — so when the cell needs ribose but not NADPH it can run F6P + G3P → R5P. RBC transketolase activity is the lab test for thiamine deficiency.
Made from Xylulose-5-phosphate by Transketolase
Transketolase — HMP shunt (pentose phosphate pathway)
Cofactors: TPP (thiamine, B₁)