3.1.3 lipids Flashcards Preview

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Triglycerides and phospholipids are two groups of lipid



Triglycerides are formed by the condensation of one molecule of glycerol (CH2OH) and three molecules of fatty acid



A condensation reaction between glycerol and a fatty acid (RCOOH) forms an ester bond



The 'R' group of a fatty acid may be saturated or unsaturated



If something is saturated it has no double bonds



If something is unsaturated It has either

One double bond between carbon atoms -> monounsaturated


More than one double bond between carbon atoms -> polyunsaturated



In a phospholipid one of the fatty acids of a triglyceride is substituted by a phosphate containing group so there's one molecule of glycerol bonded too two fatty acids and then a phosphate contains group



The different properties of phospholipids and triglycerides relate to their different structures.



The test for lipids is know as the emulsion test . Ethanol is added to a solution that potentially could contain lipids , the test tube is then shaken and water is added to it , a positive result would be indicated by the formation of a cloudy white suspension , if a negative result occurs the solution will remain colourless.