Lipids - fat reserve of body

             Our body contains fats on it this fat is nothing but lipids. This lipids acts as insulators like in polar bear 2 CM layer of fat is present which protects it from cold know as insulator. 

              Defining lipids is nothing but organic substances relatively insoluble in water and soluble in organic solvents eg alcohol, Actually or potentially related to fatty acids and utilised by living cells. 

               So lipids are organic substances as a well cooked oily food when falls on shirt it not get washed by water because of their property and stain remains. Therefore we use detergents to wash them all. 

               Classification of lipids is carried out by chemical groups they contains. First is simple lipids. Simple lipids are esters of fatty acids with alcohols eg fat and oils. Difference between oil and fat is oil is liquid at room temperature while fat is solid at room temperature. 

                Complex lipids as name suggests this are complex which contains additional group such as phosphates, carbohydrates or proteins in their simple structure. 

                  Derived lipids are third type of lipid by hydrolysis of simple and complex lipids. Eg steroid hormones. Steroid hormones are produced by hydrolysis of simple and / or complex lipids. 

               Fourth is miscellaneous lipids carotenoids present in carrots as carotene and pentacosane present in bee wax. Alpha carotene and beta carotene present in carrot responsible for good eye sight is lipid Or miscellaneous lipid. 

               Fifth is neutral lipid eg cholesterol which is responsible for blockage of veins when consumed in large amount is neutral lipid. 

                 Now what are functions of them? They acts as concentrated fuel reserve of our body like again fishes and polar bear present on North Pole can hybernate for months without food as they contain good amout of lipid as reserve. They acts as carrier of vitamin A, D,E, K which gets solubalised in lipids. They regulate metabolism as steroid hormones.  

               So this all was about lipids which are oily stain on cloth, fats on polar bear, reserve oil of human body, carotene found in carrot and steroid ingested by athletes.