3.1.3 lipids Flashcards
Triglycerides and phospholipids are two groups of lipid
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Triglycerides are formed by the condensation of one molecule of glycerol (CH2OH) and three molecules of fatty acid
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A condensation reaction between glycerol and a fatty acid (RCOOH) forms an ester bond
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The ‘R’ group of a fatty acid may be saturated or unsaturated
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If something is saturated it has no double bonds
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If something is unsaturated It has either
One double bond between carbon atoms -> monounsaturated
Or
More than one double bond between carbon atoms -> polyunsaturated
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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
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The different properties of phospholipids and triglycerides relate to their different structures.
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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.
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