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.
Lipolysis, carnitine shuttle & β-oxidation · Adipose (lipolysis) → mitochondrial matrix (β-oxidation); peroxisomes for very-long-chain. 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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Lipolysis, carnitine shuttle & β-oxidation
3-Ketoacyl-CoA
Made from L-3-Hydroxyacyl-CoA by 3-Hydroxyacyl-CoA dehydrogenase
3-Hydroxyacyl-CoA dehydrogenase — Lipolysis, carnitine shuttle & β-oxidation
Cofactors: NAD⁺ → NADH
Inhibited by: High NADH (ethanol)
Second oxidation. This is the step that ethanol's NADH load stalls → fatty liver.
Becomes Acetyl-CoA (+ acyl-CoA −2C) via Thiolase (β-ketothiolase)
Thiolase (β-ketothiolase) — Lipolysis, carnitine shuttle & β-oxidation
Cofactors: CoA
Releases acetyl-CoA; the acyl-CoA (2 carbons shorter) goes around again.