– It include oils, phospholipids, glycolipid, sreroids, etc
– Triglyceride forms about 95% of all lipids and other forms about 5%.
– Lipids are insoluble in water but soluble in organic solvent like ethers .
– Fats (solid at room temp.) ,oils (liquid at room temp.).
– Energy source each 1gm. Produce 9 Kcal in complete oxidation ( It Produce more Energy because of more Hydrogen atoms to Oxygen atoms and the chief energy in the adipose tissue).
– Protection of Vital organ. (4% of total fat serves as shock absorber)
– Keeping of body Temp.
– Carrier of fat soluble Vit. A,D,E and K.
– Precursors of important compounds such as steroid hormones.
– Satiety , ingestion of lipids delay the onset of hunger.
– It is the major compound of all cellular membranes.
– Simple Lipids. i.e. Triglycerol.
– Compound Lipids.
– Formed by simple fats combined with additional chemicals (i.e. lipoproteins, phospholipids, glycolipid)
– Derived Lipids.
– made up of simple and compound fats
– Steroids: including Cholesterol , bile acid, and salts. Steroid hormones and ergosterol (Vit D Precursor).
– Eicosanoids : they are long chain fatty acids composed of 20 carbon atoms. They include prostaglandin, thromboxane, leckoriones and prostacyclin.
They are derived from W3 and W6 fatty acids and have regulatory function inside the body.
c. Fat soluble Vitamins (A,D,E and K.)
d. Glycerol and farry acid.
– Triacylglycerol is the main form of fats in foods stuffs and storage lipids. On hydrolysis Triacylglycerol produce glycerol and fatty acids as it is an esrer of fatty acid and glycerol.
1- According to the number of carbon atoms:
2- According to saturation by hydrogen atoms:
– (Bonding of carbons and arrangement of hydrogens along carbon chain)
1)Saturated fatty acids
– Only single bonds linking carbons
– Found in animal products, dairy fats, coconut & palm oil, vegetable shortening, and margarine.
2) Unsaturated fatty acids
– Have at least one double bond
– Monounsaturated – one double bond (Oleic W9)
– Olive, peanut, and canola oils
– Polyunsaturated – 2+ double bonds
(Linoleic W6 2 D.P , Linolenic W3 3 D.P, Arachidonic 4 D.P)
– Sunflower, soybean, corn, & safflower oils
3) According to it’s nutritional value:
– Nonessential fatty acid: which can be produce inside the body. i.e.: palmetic.
– Essential fatty acid: which can’t be produce inside the body. i.e: Linoleic W6 , Linolenic W3 , Arachidonic.
– Functions of W3:
– This f.a found in fish oil, W3 and W6 are precursor of PGs and other related copounds which have the following functions:
– They reduce blood TG and cholesterol level.
– They prevent blood clot formation, on arterial wall.
– They prevent progression of atherosclerotic heart disease.
– They enhance defense against cancer
– its main function is to transfer lipids such as cholesterol via the blood stream.
– It helps the body to sustain its nerve cells and other vital cells in our body.
– it also helps the lipids to transport energy to the muscles.