Triglyceride or Fatty acids : Definition, classification and function
In the dehydration reaction, one molecule of glycerol and three molecules of fatty acid combine to form simple lipids called triglycerides. Triglyceride is an alcohol. It contains 3 carbon and 3 hydroxy groups. Fatty acids are hydrocarbon chains and contain carboxyl groups. Linkage of OH side group through dehydration reaction of carboxyl group is called ester linkage. There are two types of triglycerides. Saturated or unsaturated and unsaturated. Dr. Siddiq Publications
1. Saturated
A fatty acid whose hydrocarbon chain is joined by a single bond (C-C) is called a saturated fatty acid. Its molecular symbol is CH3(CH2)nCOOH (n=18). It accumulates in the artery walls and stops blood flow. The result is heart disease. Such as lauric acid, palmitic acid, stearic acid, linoseric acid etc.
Properties of saturated fatty acids
(i) Carbon atoms of saturated fatty acids are joined by covalent bonds.
(ii) Its melting point is relatively high.
(iii) It is not an essential fatty acid.
(iv) It is high in animal fat.
(v) It remains solid at normal temperature (200C).
2. Unsaturated
Fatty acids that have a double or triple bond (C=C) in their hydrocarbon chain are called unsaturated fatty acids. Humans and mammals cannot form a double bond after the 9th carbon of a fatty acid. So we need to add some unsaturated fatty acids to our diet. This is why linoleic and linolenic acids are called essential fatty acids. Plant-derived unsaturated fatty acids are beneficial for human health. So the lack of nutrients in the body is fulfilled. For example, oleic acid, linoleic acid, linolenic acid etc.
Properties of unsaturated fatty acids
(i) Carbon atoms of unsaturated fatty acids are joined by divalent bonds.
(ii) Its melting point is relatively low.
(iii) It is an essential fatty acid.
(iv) It is high in phytonutrients.
(v) It is liquid at normal temperature (20°C).