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Pharos university Faculty of Allied Medical SCIENCE Biochemistry 1 ( MGBC-201 )

Pharos university Faculty of Allied Medical SCIENCE Biochemistry 1 ( MGBC-201 ). Dr . Tarek El Sewedy Department of Medical Laboratory Technology Faculty of Allied Medical Sciences. Lecture. Lipids and Fatty acids (1). Intended Learning Outcomes.

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Pharos university Faculty of Allied Medical SCIENCE Biochemistry 1 ( MGBC-201 )

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  1. Pharos universityFaculty of Allied Medical SCIENCEBiochemistry 1(MGBC-201) Dr. Tarek El Sewedy Department of Medical Laboratory Technology Faculty of Allied Medical Sciences

  2. Lecture Lipids and Fatty acids (1)

  3. Intended Learning Outcomes • By the end of this lecture, students will learn: • General structure and functions of lipids. • How to write the chemical formula of fatty acids. • Classification of fatty acids. • Lipid Nutritional facts.

  4. Lecture Content • Lipids and fatty acids structure . • Physiological role of fatty acids. • Classification of lipids. • Nomenclature of fatty acids. • Classification of fatty acids. • Fats and diet

  5. Lipids • Lipids are heterogeneous compounds composed of C,H and O and may contain P, N and S. • They includes fats, waxes, phospholipids, and other physical-propertiesrelated compounds. • They have the common physical property of being: • Insoluble in water • Soluble in nonpolar solvents such as ether and chloroform. • The monomers of lipids are fatty acids.

  6. Fatty acids • Fatty Acids Are Key Constituents (Monomers) of Lipids • Among the most biologically significant properties of lipids are their hydrophobic properties. • This property is mainly due to a particular component of lipids: fatty acids

  7. Structure of Fatty Acids Fatty acids are hydrocarbon chains of various lengths and degrees of unsaturation that terminate with carboxylic acid groups. a. Stearic acid (saturated) B. Oleic Acid (unsaturated) The physical characteristics of the fatty acid  (e.g. number of double bonds) determine its biochemical properties (e.g. solubility, melting point)  Fats containing a high proportion of saturated fatty acids, such as butter, have a relatively high melting temperature and tend to be solid at room temperature. Most vegetable oils, which contain higher levels of monounsaturated or polyunsaturated fats, are usually liquid at room temperature.

  8. Physiological role of fatty acids First, fatty acids are building blocks of phospholipids and glycolipids. These molecules are important components of biological membranes. Second, many proteins are modified by the covalent attachment of fatty acids, which targets them to membrane locations. Third, fatty acids are fuel molecules. They are oxidized to meet the energy needs of a cell or organism. Fourth, fatty acid derivatives serve as hormones and intracellular messengers.

  9. Lipids & Energy

  10. 1. Classification of lipids • Simple • Complex • Precursor or Derived

  11. Classification of lipids • LIPIDS ARE CLASSIFIED AS SIMPLE OR COMPLEX Or DERIVED A. Simple lipids: Esters of fatty acids with various alcohols. • Fats: Esters of fatty acids with glycerol. • Waxes: Esters of fatty acids with higher molecular weight alcohols. (Fatty Acid)

  12. A. Simple lipids Esters of fatty acids with various alcohols. (Fatty Acid) (Fat)

  13. Ester Bond (Simple Lipid) FAT

  14. Triacylglycerol(Triglycerides) • Glycerol: Three carbon tri-alcohol. • Fatty acids: aliphatic carboxylic acids. • Could be monoglycerides, diglycerides, or triglycerides, depending on whether there are one, two, or three fatty acid chains present in the molecules.

  15. b. Complex lipids • Esters of fatty acids containing groups in addition to an alcohol and a fatty acid. • a. Phospholipids: Lipids containing, in addition to fatty acids and an alcohol, a phosphoric acid residue. • b. Glycolipids: Lipids containing a fatty acid, alcohol, and carbohydrate. • C.Other complex lipids: Lipids such as sulfolipidsand Lipoproteins.

  16. Lipids in Cell Membrane (Phospholipds) 1 glycerol + 2 fatty acids + 1 phosphate group + 1 organic functional group = phospholipid Phosphate groups – Interacts with water; because the phosphate head is polar. Fatty acid ‘legs’ – Non-polar, do not interact with water and align themselves together to be protected from the water while exposing the phosphate groups to the water.

  17. C. Derived lipids • These include lipid-soluble vitamins, and hormones.

  18. Nomenclature of Fatty Acids • The name for a fatty acid is derived from the name of its parent hydrocarbon by the substitution of oicfor the final e. ex. the C18fatty acid is called octadecanoicacid because the parent hydrocarbon is octadecane (18) • The notation 18:0denotes a C18 fatty acid with no double bonds, whereas (18:3n 9,12,15) signifies that there are three double bonds at position 9,12 and 15 of carboxyl carbon. • Carbon atoms are numbered from the carboxyl carbon (carbon No. 1). The carbon atoms adjacent to the carboxyl carbon (Nos. 2, 3, and 4) are also known as the α, β, and γ carbons, respectively, and the terminal methyl carbon is known as the ω or n-carbon

  19. I-According to number of carbon atoms Short chain long chain 2-10 C atoms>10 C atoms Butyric acid (4 C) Palmitic acid(16C)

  20. II-According to presence or absence of double bond Saturated unsaturated MonounsaturatedPolyunsaturated Palmitic acid, Butyric acid, Caproic acid, Stearic acid Linoleic acid C18 Linolenic acid C18 Arachidonic acid C20 Oleic acid C18 Nervonic acid C24

  21. Common Unsaturated Fatty Acids

  22. Unsaturated fatty acid are classified into Cis trans • Cis and trans are terms that refer to the arrangement of the two hydrogen atoms bonded to the carbon atoms involved in a double bond. In the cis arrangement, the hydrogens are on the same side of the double bond. In the trans arrangement, the hydrogens are on opposite sides of the double bond

  23. III-According to nutrition state EssentialNon essential Sarurated FA Monounsaturated FA Polyunsaturated Linoleic acid C18 Arachidonic acid C20

  24. 1-Non essential fatty acids: They can be synthesized in the human body All saturated and monounsaturated FA's Ex: Palmitoleic acid ( 16:1n;∆9) CH3(CH2)5CH=CH(CH2)7COOH higher concentrations in the liver Ex: Oleic acid; ( 18:1n;∆9) majority of olive oil

  25. 2- Essential fatty acids Polyunsaturated fatty acids Need to get them from diet because the body cannot manufacture them. Alpha linolenic acid (18:3n;∆9,12,15): is the so-called "parent" fatty acid for the omega 3 family of fatty acids because the liver can make other omega 3 fatty acids from it.

  26. linoleic acid (LA)(18:2n; ∆9,12); Is the "parent" fatty acid for the synthesis of other omega 6 fatty acids in the liver.  It is found in the lipids of cell membrane. It is abundant in many vegetable oils, and sunflower oils.

  27. Arachidonic acid (20;4n;5,8,11,14) Repair and Growth of skeletal muscle tissue Abundant fatty acids in the brain Play a central role in inflammation

  28. Students selected for assignment

  29. ASSIGNMENTS • Selected students are requested to prepare slides about one of the following topics (To be delivered before next lecture): • Lipids and disease • Healthy lipids • Unhealthy lipids • Atherosclerosis • Saturated Fatty acids • Unsaturated fatty acids • Triglyceridss

  30. Complete: • -----------,--------------------and------------------are essential fatty acids. • ----------------and --------------are saturated fatty acids. • All --------------and---------------are non essential amino acids. • ----------------------- is the parent compound of glycerophspholipids. • Lipids includes three main classes which are-----,--------and-------- Study Questions

  31. 1-Essential amino acids are synthesized in human body. 2-Saturated fatty acids have one or more double bonds. 3- Alpha linolenic acid is non-essential amino acid. 4- Palmitoleic acid is essential amino acid. Correct the incorrect word:

  32. Principles of Biochemistry, Donald J. Voet, Judith G. Voet, Charlotte W. pratt; Willey, 3rd ed. Suggested readings

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