Theoretical Basis Lipid

THEORETICAL BASIS LIPID The term lipid is used to describe natural compounds of fatty acid esters long chains that can be saponified. This organic compound can be extracted by nonpolar solvents such as chloroform, ether, benzene, acetone and alcohol. Lipids are present in all cells and functions as a component of cell structure, as a store metabolic fuel, as a form of compound to transport fuel, as a protective component of vertebrate cell walls and skin. Some lipids has biological activities that are very important for the body such as vitamins and hormone. From a nutritional perspective, apart from acting as a vitamin solvent, Fat is an important source of calories. One gram of lipid provides calories and water as much as 2 times the number of calories and water produced from carbohydrates. Lipids often bind to other compounds such as carbohydrates (eg glycolipids) and proteins (as lipoproteins). Bloor classifies lipids into 3 groups, namely: A. Simple Lipids These lipids, when hydrolyzed, only produce fatty acids and alcohol. Simple lipids are divided into two groups, namely: 1. Fat, namely fatty acid esters with glycerol. 2. Waxes, namely fatty acid esters with high aliphatic alcohols with 10- 40 carbon atoms. B. Compound Lipids This group is an ester of a fatty acid with an alcohol contain other groups such as phospholipids (glycerophosphatides), cerebroside, glycolipid, sulfolipid, sphingolipid, sphingomyelin, aminolipid and lipoproteins. C. Lipid Derivatives (Lipid Derivatives) Lipid derivatives are the result of hydrolysis of simple lipids and lipids compound. This group includes fatty acids, glycerol, steroids, alcohol, aldehydes and ketones. HOW IT WORKS SOLUBILITY TEST The solubility of a substance, especially a fat, can be tested by dissolving a small amount the substance into a few milliliters of solvent. The degree of solubility of substances can be determined by direct observation or if it is not enough, the liquid can be decanted (filtered through dry filter paper) into a watch glass. Then solution evaporated over a water bath. The presence or absence of residue indicates the presence or absence whether or not the substance is in the solvent. Ways of working: A. Grease Stain Test 1. Provide 5 test tubes, and fill them 2. Stir well, then take a little of the solution and drop it on top filter paper. 3. Let the filter paper dry then observe whether there are fat spots or not on that paper. B. 1. Put a small amount of fat (the size of a match head) into the tube reaction. 2. Add 2 ml of water and heat over a boiling water bath. 3. See what happens, then add 5 ml of NaOH solution in alcohol and heat again until a clear solution forms. 4. Shake and watch for foam to form, why? C. 1. Put 1 ml of coconut oil and 3 ml of water into a test tube, shake. 2. Add 2 ml of water and heat over a boiling water bath. 3. Pay attention to what happens. 4. Add 1 ml Na2CO3 0.5%. Shake again and see what happens happen. 5. What is the effect of Na2CO3 on emulsion stability? D. 1. Provide 5 test tubes, and fill them 2. Add a little palmitic acid into each tube, stir. 3. Perform a fat stain test as in point A. 4. Observe the fat spots that form on the filter paper. E. 1. Provide 4 test tubes, and fill them 2. Stir well, then pay attention to the liquid that sticks to the walls tube and taste it. 3. Perform a fat stain test as in point A. 4. Wash the grease stains on the filter paper with water and then dry the paper filter it. 5. Observe the presence or absence of grease stains, and write down the difference from the points D. SMELL TEST Ways of working: 1. Provide 3 test tubes and fill them with: - Tube a: 3 drops of edible oil. - Tube b: 3 drops of glycerol. - Tube c: 3 drops of palmitic acid. 2. Heat each tube carefully over the flame of a lighter. 3. Smell the odor that comes out and conclude the difference in odor that arises. UNSATISFACTION TEST Ways of working: 1. Provide 3 test tubes and fill them with: - Tube a: a little oleic acid and 2 ml of chloroform. - Tube b: a little palmitic acid and 2 ml of chloroform. - Tube c: a little edible oil and 2 ml of chloroform. 2. Add 3 drops of Hubl iodine solution and shake gently until mixed. 3. Note the change in color of Iodine in the solution. 4. Explain the differences in the results of each tube and write the equation the reaction. ACROLEIN TEST Ways of working: 1. Provide 3 test tubes and fill them with: - Tube a: 10 drops of edible oil. - Tube b: 10 drops of glycerol. - Tube c: a little palmitic acid. 2. Add KHSO4 crystals into each tube in the same volume The same. 3. Heat it carefully and smell the smell that comes out. 4. Write the equation for the reaction that occurs.