Biochemistry of Lipids 01.pptx
- 1. Duration: 10 min Veterinary Biochemistry By: Dr. Rahil Razak Bhat rahilrazak192@gmail.com Lipids-part I Animal Biochemistry Disease Diagnosis Vetybiochemi By Rahil Razak Bhat
- 2. Biochemistry of Lipids By: Dr. Rahil Razak Bhat Classification and biological significance
- 3. Definition of lipids ▪ Lipids are defined as diverse, structurally heterogeneous, hydrophobic or amphiphilic small water-insoluble compounds extracted from living organisms by weakly polar or nonpolar solvents (chloroform, acetone, ether etc).
- 4. Distinguishing property of lipids ▪ The definition is based on a physical property in contrast to the definitions of the other basic building blocks (proteins, carbohydrates, and nucleic acids), which are based on chemical structure. ▪ Lipids are not made from monomeric units like other macromolecules ( proteins, polysaccharides, Nucleic acids-DNA & RNA).
- 5. Lipids: Definition ▪ The LIPID MAPS consortium (http://www.lipidmaps.org) in the United States, Lipid Bank (http://www.lipidbank.jp) in Japan and the LipidomicNet (http://www.lipidomicnet.org) in Europe have cooperated to devise classification systems, methodology and forums for the benefit of researchers. ▪ Consequently the term lipid covers a structurally diverse group of compounds including fatty acids, glycerolipids, sphingolipids, terpenes, steroids, and carotenoids.
- 6. Biological significance of Lipids ▪ Lipids or fats have structural or signalling functions in the body, in addition to their major role in energy storage. ▪ Dietary fats have a very high energy content. ▪ Fats PROTECTIVE FUCTION IN INSECTRS, PLANTS, ANIMALS. ▪ Fats are also used for synthesis of specialized signalling molecules, such as prostaglandins, thromboxanes, and leukotrienes. ▪ Biological lipids serve as cofactors likeVit K, as hormones likeVit D, as detergents like bile salts (cholic, deoxycholic, chenodeoxycholic, and lithocholic acids)
- 11. Examples Esters of Fatty acids and alcohol=glycerol inTAGs, and High MolecularWeight Alcohol in Waxes Ester of Fatty acids and various alcohols Simple Lipids Fats/Mono/Di/Triacylglycerols /triglycerides(neutral fats) SimpleTAGs: tripalmitin, tristearin MixedTAGs: 1-lauro-2 - myristopalmitin Waxes BeeWax. Triacontaryl palmitate
- 12. Simple Lipids ▪ Fats and waxes are simple lipids. ▪ Fats: Are esters of fatty acids with glycerol. ▪ Triglycerides, diglycerides and mono glycerides are fats. ▪ Triglyceride is also called as tri acyl glycerol.
- 14. Biological significance of fats ▪ They are mainly involved in energy storage and transport function. ▪ Adipose tissue present under skin contains triglycerides. ▪ In the abdomen, thighs and in mammary gland, adipose tissue or fat tissue contains triglycerides/tri acyl glycerol or neutral fats.
- 15. ▪ In hibernating animals, seals and penguins triglycerides are more. ▪ Fat under the skin has dual roles. It function as energy store as well as insulator against cold.
- 16. Waxes ▪ Are esters of fatty acids with HMW alcohols ▪ Wool and bees waxes are waxes known well. ▪ Wool wax, Lanolin, is ester of fatty acid with long chain alcohol lanosterol and agnosterol. ▪ Bees wax is an ester of fatty acid palmitic acid withTriacontanol alcohol.
- 17. Biological significance of waxes ▪ Waxes form protective layer over the skin, fur, feathers of animals. Shiny appearance of fruits, leaves of plants are due to waxes. ▪ Waxes are hard at low temperature and soft at high temperature. ▪ Lanolin a wax of animal origin is used as protection against low temperature or cold. ▪ Woollen clothing protect us from cold for this reason. ▪ Waxes act as water barrier for animal, plants, birds etc
- 18. Fatty acids ▪ Fatty acids, the simplest lipids, can be oxidized to generate much of the energy needed by cells in the fasting state (excluding brain cells and erythrocytes). ▪ 2. Fatty acids are precursors in the synthesis of more complex cellular lipids (e.g., triacylglycerol). ▪ 3. Only two fatty acids are essential and must be supplied in the diet: linoleic acid and Linolenic acid.
- 19. Fatty Acids ▪ Fatty acids are carboxylic acids with hydrocarbon chains ranging from 4 to 36 carbons long (C). In some fatty acids, this chain is unbranched and fully saturated (contains no double bonds); in others the chain contains one or more double bonds.
- 20. Fatty Acids ▪ The most commonly occurring fatty acids have even numbers of carbon atoms in an unbranched chain of 12 to 24 carbons. Some books write 6 to 36 ▪ Successive double bonds are separated by methylene group (-CH2-) in PUFA. ▪ In nearly all naturally occurring unsaturated fatty acids, the double bonds are in the cis configuration. ▪ Trans fatty acids are produced by fermentation in the rumen of dairy animals and are obtained from dairy products and meat.
- 21. Fatty Acids ▪ In vertebrates, free fatty acids (unesterified fatty acids, with a free carboxylate group) circulate in the blood bound non-covalently to a protein carrier, serum albumin. ▪ Fatty acids are present in blood plasma mostly as carboxylic acid derivatives such as esters or amides. ▪ Lacking the charged carboxylate group, these fatty acid derivatives are generally even less soluble in water than are the free fatty acids.
- 22. About fatty acids ▪ A few contain three-carbon rings, hydroxyl groups, or methyl group branches. ▪ They vary in chain length and degree of unsaturation (number of double bonds). Nearly all have an even number of carbon atoms. ▪ Most consist of linear chains of carbon atoms, but a few have branched chains. ▪ Fatty acids occur in very low quantities in the free state and are found mostly in an esterified state as components of other lipids. ▪ Fatty acids are based on the following formula: CH3(CH2)nCOOH.
- 23. Essential Fatty acids ▪ These are unsaturated fatty acids which are not manufactured by human body. ▪ Like alpha Linolenic acid, Linoleic acid. ▪ Arachidonic acid is also regarded as essential fatty acid but is formed from above two fatty acids.
- 24. Duration: 10 min Veterinary Biochemistry By: Dr. Rahil Razak Bhat rahilrazak192@gmail.com Lipids-part I Animal Biochemistry Disease Diagnosis Vetybiochemi By Rahil Razak Bhat
- 25. Classification of Fatty acids 1.Chain length 2.Total carbon Numbers 3.Nature of Chain 4.synthesis Short chain: C2-C6. eg: acetic acid Propionic acid, Butyric acid,Valeric acid Medium Chain C8-C14 Eg: Lauric acid, Myristic acid Long Chain: C16-24. Eg: oleic, palmitic, Linolenic acids Very long chain: C>24 Triacontanoyle Odd Number • Propionic acid Even Number Unbranched Branched: Isovaleric acid Hydroxy Fatty acids Eg: Cerebronic acid Essential Fatty acids: • Linoleic acid • α-Linolenic acid Non essential fatty acids: 5. Degree of saturation Saturated Unsaturated • PUFA • MUFA On the basis of
- 26. Fatty acids Saturated Unsaturated Palmitic acid (C16:0), stearic acid (C18:0), Lauric acid (C12:0), myristic acid (C14:0) Arachidic acid (C 20:0) Lignoceric acid (C24:0) Monounsaturated Fatty Acids, MUFA: Palmitoleic acid (C16:1 ∆9), Oleic acid (C 18:1 ∆9) . Polyunsaturated Fatty acids, PUFA: Linoleic acid (C18:2 ∆9, 12 ), Linolenic acid (C18:3 ∆9, 12 ,15 ) Arachidonic acid (C20:4 ∆5, 8, 11, 24) The physical properties of the fatty acids, and of compounds that contain them, are largely determined by the length and degree of unsaturation of the hydrocarbon chain.
- 27. Nomenclature Two types ▪ C system and ▪ Omega system Cis-9-octadecaenoic acid carbon skeleton: 18:1 (∆9)
- 28. Melting points are also strongly influenced by the length and degree of unsaturation of the hydrocarbon chain. This difference in melting points is due to different degrees of packing of the fatty acid molecules In the fully saturated compounds, free rotation around each carbon-carbon bond gives the hydrocarbon chain great flexibility; the most stable conformation is the fully extended form, in which the steric hindrance of neighbouring atoms is minimized. These molecules can pack together tightly in nearly crystalline arrays, with atoms all along their lengths in van der Waals contact with the atoms of neighboring molecules. In unsaturated fatty acids, a cis double bond forces a kink in the hydrocarbon chain. Fatty acids with one or several such kinks cannot pack together as tightly as fully saturated fatty acids, and their interactions with each other are therefore weaker. Because less thermal energy is needed to disorder these poorly ordered arrays of unsaturated fatty acids, they have markedly lower melting points than saturated fatty acids of the same chain length.
- 29. Nomenclature of Fatty acids ▪ A simplified nomenclature for unbranched fatty acids specifies the chain length and number of double bonds
- 31. Saturated FA Monounsaturated FA Polyunsaturated FA Polyunsaturated FA
- 34. Triacylglycerols Are Fatty Acid Esters of Glycerol ▪ The simplest lipids constructed from fatty acids are the triacylglycerols, also referred to as triglycerides, fats, or neutral fats. Triacylglycerols are composed of three fatty acids each in ester linkage with a single glycerol. ▪ Those containing the same kind of fatty acid in all three positions are called simple triacylglycerols and are named after the fatty acid they contain. ▪ Simple triacylglycerols of 16:0, 18:0, and 18:1, for example, are tripalmitin, tristearin, and triolein, respectively. ▪ Most naturally occurring triacylglycerols are mixed;They contain two or three different fatty acids.To nameThese compounds unambiguously, the name and position of each fatty acid must be specified.