Lipid metabolism

Lipid metabolism is the synthesis and degradation of lipids in cells, involving the breakdown and storage of fats for energy and the synthesis of structural and functional lipids, such as those involved in the construction of cell membranes. In animals, these fats are obtained from food and are synthesized by the liver.[1] Lipogenesis is the process of synthesizing these fats.[2][3] The majority of lipids found in the human body from ingesting food are triglycerides and cholesterol.[4] Other types of lipids found in the body are fatty acids and membrane lipids. Lipid metabolism is often considered the digestion and absorption process of dietary fat; however, there are two sources of fats that organisms can use to obtain energy: from consumed dietary fats and from stored fat.[5] Vertebrates (including humans) use both sources of fat to produce energy for organs such as the heart to function.[6] Since lipids are hydrophobic molecules, they need to be solubilized before their metabolism can begin. Lipid metabolism often begins with hydrolysis,[7] which occurs with the help of various enzymes in the digestive system.[2] Lipid metabolism also occurs in plants, though the processes differ in some ways when compared to animals.[8] The second step after the hydrolysis is the absorption of the fatty acids into the epithelial cells of the intestinal wall.[6] In the epithelial cells, fatty acids are packaged and transported to the rest of the body.[9]

Metabolic processes include lipid digestion, lipid absorption, lipid transportation, lipid storage, lipid catabolism, and lipid biosynthesis. Lipid catabolism is accomplished by a process known as beta oxidation which takes place in the mitochondria and peroxisome cell organelles.

  1. ^ "Overview of Lipid Metabolism". Merck Manuals Professional Edition. Retrieved 2016-11-01.
  2. ^ a b "Hydrolysis – Chemistry Encyclopedia – structure, reaction, water, proteins, examples, salt, molecule". chemistryexplained.com. Retrieved 2016-11-01.
  3. ^ Freifelder D (1987). Molecular biology (2nd ed.). Boston: Jones and Bartlett. ISBN 978-0-86720-069-0.
  4. ^ Baynes D (2014). Medical Biochemistry. Saunders, Elsevier Limited. pp. 121–122. ISBN 978-1-4557-4580-7.
  5. ^ Arrese EL, Soulages JL (2010). "Insect fat body: energy, metabolism, and regulation". Annual Review of Entomology. 55: 207–25. doi:10.1146/annurev-ento-112408-085356. PMC 3075550. PMID 19725772.
  6. ^ a b Lehninger AL, Nelson DL, Cox MM (2000). Lehninger Principles of Biochemistry (3rd ed.). New York: Worth Publishers. ISBN 978-1-57259-931-4.
  7. ^ Ophardt CE (2013). "Lipid Metabolism Summary". Virtual Chembook. Elmhurst College.
  8. ^ Wedding RT (May 1972). "Reviewed Work: Plant Lipid Biochemistry". The New Phytologist. 71 (3): 547–548. JSTOR 2430826?.
  9. ^ Jo Y, Okazaki H, Moon YA, Zhao T (2016). "Regulation of Lipid Metabolism and Beyond". International Journal of Endocrinology. 2016: 5415767. doi:10.1155/2016/5415767. PMC 4880713. PMID 27293434.