- Fatty acid synthesis and storage are essential components of body energy homeostasis.
- Lipogenesis takes place in the cytosol. Its committed step is the reaction catalyzed by acetyl CoA carboxylase.
- The elongation of the fatty acid chain (up to the length of 16 carbon atoms) is carried out by the dimeric fatty acid synthase, which possesses several enzyme activities. Both are subject to a complex regulation.
- The malate shuttle facilitates the transfer of two-carbon units form the mitochondria to cytoplasm for use in lipogenesis.
- The reducing power in the form of NADPH is supplied by the pentose phosphate pathway and also by the malate shuttle.
- The essential unsaturated fatty acids are linoleic and linolenic acid. Linoleic acid is converted to the arachidonic acid, which in turn serves as the precursor of prostaglandins.
- Adiposity signals are provided by adipokines, particularly leptin. Insulin is also important in the regulation of food intake.
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- Describe how a growing fatty acid chain is transferred between the subunits of fatty acid synthase.
- How are eicosanoids synthesized?
- Explain why the rate of lipolysis in the fed state is low.
- What is the role of adipokines?
- Describe the committed step of lipogenesis and its regulation.
- What are the sources of acetyl CoA for fatty acid synthesis?
- Compare and contrast lipogenesis and lipolysis.
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| Kopelman PG. Obesity as a medical problem. Nature 2000;404: 635-43.
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| Semenkovich CF. Regulation of fatty acid synthase (FAS). Progress in Lipid Research 1997:36:43-53.
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Angulo P. Nonalcoholic fatty liver disease. N Engl J Med 2002;346:1221-31.
Full article
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| Cock T-A, Auverx J. Leptin: cutting the fat off the bone. Lancet 2003;362:1572-74.
Full article
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