Simple Lipid Chemistry Lecture 1 PDF

Lipid Chemistry Lecture 1 Simple lipids  Prof / Ayman El Baz Professor of Medical Biochemistry & Molecular Biology Dr/ Sara El Derbaly Assistant Professor of Medical Biochemistry& Molecular Biology 1. Define lipids. 2. Summarize the biological imp...

Lipid Chemistry Lecture 1 Simple lipids  Prof / Ayman El Baz Professor of Medical Biochemistry & Molecular Biology Dr/ Sara El Derbaly Assistant Professor of Medical Biochemistry& Molecular Biology 1. Define lipids. 2. Summarize the biological importance of lipids. 3. Classify lipids 4. Describe the structure and function of fatty acids and glycerol.  Definition of lipid Hydrophobic Substance (water-hater) Lipids are compounds which are relatively insoluble in water, but freely soluble in non- polar organic solvents like benzene, ether, acetone or chloroform. Importance of lipids not Imp Very 1. Source of energy: they yield twice the energy (9 calories/gm) produced by the same weight of carbohydrates or proteins (4 calories/gm) (in absence of carbohydrates). 2. Energy store in adipose tissue. 3. They contain important dietary constituents as: Fat-soluble vitamins (A, D, E and k) The Essential Fatty Acids 4. Lipids serve as a thermal insulator in the subcutaneous tissues and as an electrical insulator for nerve fibers 5. Lipids give protection to certain organs e.g., kidneys 6. They provide important cellular structures for cell membranes and mitochondria  Classification of Lipid Simple lipid Compound lipid Derived lipids Pare lipids Conjugated Formed of Formed of Substances derived from fatty acids lipid part simple lipids and + + compound lipids by hydrolysis. fatty alcohol non-lipid part Fats and Oils (alcohol Phospholipids. in cell memb Fatty acids is glycerol) Glycolipids glycerol & mainly Galactose Waxes (alcohol is high Sulpholipids Steroids molecular weight Lipoproteins * Fat soluble vitamins myricyl alcohol) proteinsipid * when you break down the simple lipid [hi the (fatty A A fatty Alcohol) each. is ganna become one alone and it'll be the derived lipids in. Simple lipids ↑ Definition Glycerol Fatty acids Definition of simple lipids They are esters of fatty acids with fatty alcohol... (Ester bond) 1 R – COOH + HO – CH2 RCO – O – CH2 + H2O Fatty acid + Alcohol Ester + Water  What's the hydrolytic product Example of simple lipid Fats and oil e.g. Triglycerides Fatty acid 1 Triaceylglycero Fatty acid 2 ↑ glycerol Triglycerides 3 Fatty acid 3 Glycerol  A) Glycerol  It is a polyhydric alcohol containing 3 OH groups. Glycero  It is miscible with water.  It is a colourless, odourless, viscous liquid that is sweet-tasting and non-toxic  Each OH group can be esterified with one fatty acid (FA) forming glycerides: 1. Monoacylglycerol= monoglycerides 2. Diacylglycerol=diglycerides 3. Triacylglycerol=triglycerides  Medical importance of glycerol: 1. In treatment of A) Coronary ischemic heart disease like angina (act as vasodilator) as: Nitroglycerin (sublingval) twsee ? B) Glaucoma due to its ability to dehydrate tissues from their content of water so it may · reduce intraocular pressure 2. In pharmaceutical and cosmetic preparations 3. As explosive  B) Fatty Acids (FAs) Structure of FA · A fatty acid consists of a straight chain of carbon atoms, with: Hydrogen atoms along the length of the chain and at one end of the chain (omega end) Carboxyl group (―COOH) at the other end (carboxylic or delta end) Carboxylic end Omega end CH2 cool CH3 Mecy  FA -- Saturated unsaturated bond of double band -7 no double presence Short - chain opto le the Carbon # are mainly even Long chain more than 10 Mono-pulyldoblebond) (Non-essential) Poly-ind AceticA (2) CH3-codH - Palmitic A (16C) CHT-(CH)-cool 1 Linoleic A. A 1 Palmitoleic.. - - butyric A. (YC) CH3-CH2CooH - Stearic A. (18C). (18C + 2 double bond) A. Linolenic 16 CH double bond 2 118c + 3 double bond) 2 Oleis. A.. 3 Arachidonic 4 double bond double bond + 20C 18 ( +) Classification of FA According to absence or presence of double bonds to: Saturated FAs Unsaturated FAs No double bond Presence of double bond Short chain FAs Long chain FAs Mono-unsaturated Poly-unsaturated FA (PUFA), (Essential) FAs FAs Up to 10 carbon More than 10 carbon Contains 1 double More than 1 double bond atoms. atoms bond 1. Acetic acid (2C) 1. Palmitic acid 1. Palmitoleic acid (16 1. Linoleic acid:(18C+ 2 double 2. Butyric acid (4C) (16C) C+ 1 double bond) bonds). 2. Stearic acid 2. Oleic acid 2. Linolenic acid:(18C+ 3 double (18C) (18 C+ 1 double bond) bonds). 3. Arachidonic acid:(20C+ 4 double bonds). 1. They must be taken in diet because the body cannot synthesize them 2. Essential for growth 3. Essential for synthesis of phospholipids& prostaglandins References  Vasudevan's Textbook of Biochemistry For Medical Students, 7th Edition.  Chatterjea’s Textbook of Medical Biochemistry, 8th edition.  Lippincott’s Illustrated Reviews: Biochemistry, 8th edition