All systems ↗Fatty acids arrive
Albumin carries non-esterified fatty acids; lipoprotein lipase releases fatty acids from triglyceride-rich particles near tissues.
CELLULAR ENERGY / 04
Fat enters through a regulated gate.
Fatty acids must be delivered, activated, transported, and oxidized. Long-chain substrates use the carnitine shuttle; beta-oxidation then releases acetyl-CoA and reduced electron carriers in repeated cycles.
Activation spends ATP
Acyl-CoA synthetases attach coenzyme A, forming fatty acyl-CoA. Different enzyme locations help direct fatty acids toward oxidation or synthesis.
CPT1 forms acylcarnitine
For long-chain fats, CPT1 transfers the acyl group to carnitine outside the inner membrane. Malonyl-CoA restrains this step.
Transport completes entry
A translocase exchanges acylcarnitine and carnitine; CPT2 reforms fatty acyl-CoA on the matrix side.
Oxidation begins the cycle
Acyl-CoA dehydrogenases introduce a double bond and transfer electrons through flavoproteins toward the respiratory chain.
Hydration and oxidation follow
Water is added, then the hydroxyl group is oxidized while NAD+ is reduced to NADH.
Thiolysis releases acetyl-CoA
Coenzyme A cleaves off a two-carbon acetyl-CoA, leaving a shortened fatty acyl-CoA for another turn.
Products converge downstream
Acetyl-CoA enters the TCA cycle or, in liver during fasting, ketogenesis; NADH and FAD-linked electrons support respiration.