Question

Juliana Etienne ; blanni Saint Jean Page 117 of 147 Stephanie Florant Sci 122 L'ab9 Lipids Pre-lab study questions 1. Lipids are a group of molecules that can be divided into five major subgroups based on their Structure and function in the body. Give the specific name to each of the following lipid subgroups: fatty acids ; long chain hydrocarbons with a carboxyl groups. parts of Triglycerides and phospholipids : critical mediators of immune response fat and oil in food and body contain lipid hormones and cholesterols major component of cell membranes 2. Describe the differences between saturated fatty acids and unsaturated fatty acids in terms of their chemical structures. What is a polyunsaturated fatty acid? Saturated fatty acids are where all the carbon atoms have single Bonds Between them máxing the lipid saturated ab no mete hydrogen can be added. unsaturated fatty acids ale where there is a double bond Between me or more of the Carbon atomio in the hydrocarbon chain Polyuntauturated fatty acid, is where all Hil carbon atoms have many Bunde- 3. What kinds of chemical reactions might be observed with unsaturated fatty acids that would not be observed with saturated fatty acids? Show the chemical reaction that would take place for the unsaturated fatty acid. 4. Write the equation for the esterification of glycerol and three palmitic acids. During an Esterification reaction, fatty acids and alcohols combine to form an roster, this is a condensation reaction and it produces water at its pide product. The formular of the reactants are: Palmitic acid: CHg (Cha) 14 COOH Reaction equation glycerol: C Hg Og 3CH₂ (CHal y COOH + C3 Hq OZ BAD! I + C5, Hq8 06

Answer 1

I think the only question asked is question-3, as questions 2 and 4 are already answered (written in the attached image). Asked : A chemical reaction that would happen in case of unsaturated fatty acid but not in case of saturated fatty acid. Now, in answer section of Q.2, it is already discussed the difference between a saturated and a unsaturated fatty acid. In brief and concrete way the difference is, in saturated fatty acid, all C-atoms are sp3 hybridized i.e. saturated fatty acid don't have any double or triple bond. On the other hand, unsaturated fatty acid have at least one double (or triple bond) i.e. they have sp2 or sp or both hybridized carbons. That's why these types of fatty acids are called unsaturated Now, a reaction in which double or triple bond responds but single bond can't would be the desired reaction to distinguish these two types of fatty acids. Foe simplicity, let's consider, unsaturated fatty acid had one double bond. Reaction : If the unsaturated fatty acid reacts with concentrated alkaline solution of purple coloured potassium permanganate (KMnO4) solution, after the reaction the purple colour turns to colourless. In the reaction, first reacts with the unsaturated C - C double bond and form a complex, where the oxidation state of Mn reduces to +5 from +7 (which was in KMnO4). As a result, the charge transfer band of the complex goes to IR regime and the solution become colourless. Upon acidification, the Mn-organic (fatty acid) complex yields a di-ol compound (di-ol derivative of the fatty acid). The reaction is shown below; while this reaction wouldn't happen for saturated fatty acid as it doesn't have any unsaturated C-C double bond. HI Alkaline cone. & KMnO4 sole theat (purple sole) (colourless)