Lecture on the topic: Lipids, their structure and properties. For the 1st year students of specialty “General medicine". Discipline: Chemistry. Lecturer: PhD, Associate Professor Vlassova Lenina. Karaganda 2014

 1. To consider the definition and classification of lipids. 2. To give a simple characterization of saponifiable lipids. 3. To study the chemical properties of triacylglycerols. 4. To give a characterization of complex saponifiable lipids. 6. To consider the biological role of saponifiable and unsaponifiable lipids.

 Lipids - a fat-like substance poorly soluble in water and readily soluble in nonpolar organic solvents. Depending on the ability to hydrolyze to form the salts of higher fatty acids (soaps) is divided into lipids saponifiable and unsaponifiable.

The main fatty acids in the lipid composition: saturated butyric acid C 3 H 7 COOH palmitic acid C 15 H 31 COOH stearic acid C 17 H 35 COOH

Unsaturated: Oleic acid C 17 H 33 COOH Linoleic acid C 17 H 31 COOH Linolenic acid C 17 H 29 COOH Arachidonic C 19 H 31 COOH

 U nsaponifiable lipids, are not derived from fatty acids and are not capable of hydrolysis. There are two main groups of unsaponifiable lipids : terpenes and steroids.

Terpenes. Terpenes called hydrocarbon composition (C5H8) n, wherein n = 2, are considered as isoprene oligomerization products:

 Oxygenated derivatives of terpenes called terpenoids. Terpenes and terpenoids are mainly of vegetable origin. It is essential plant oils, resins of rubber and coniferous trees, plant pigments, fat- soluble vitamins.  Menthol and validol.

 Steroids – the natural biologically active compounds, the basic structure of which is hydrocarbon-steranes. Cholesterol, bile acids, sex hormones, adrenocortical hormones, corticosteroids, cardiac glycosides are steroids.