Category: catabolism
Mitochondrial degradation of fatty acyl-CoA into acetyl-CoA + FADH2 + NADH. Long-chain fatty acids must first traverse the inner mitochondrial membrane via the CARNITINE SHUTTLE (CPT1 outer, CACT translocase, CPT2 inner) — CPT1 is the major regulatory step, inhibited by malonyl-CoA (the link to fatty acid synthesis: high malonyl-CoA → cytosolic FA synthesis ON, mitochondrial β-oxidation OFF). Each β-oxidation cycle: acyl-CoA → enoyl-CoA (FAD) → 3-OH-acyl-CoA → 3-ketoacyl-CoA (NAD) → shortened acyl-CoA + acetyl-CoA. Cycle repeats until the acyl chain is fully consumed. Carnitine deficiency (genetic or valproate-induced) presents as hypoketotic hypoglycemia + cardiomyopathy + Reye-like syndrome.