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41 2. Higher fatty acids. Definition, classification, representatives of saturated, monounsaturated and polyunsaturated fatty acids, their biological role. 3. Wax, definition, general formula, representatives of waxes. 4. Triacylglycerols (neutral fats).Definition, general formula, representatives, role. Monoacylglycerols and diacylglycerols. 5. Chemical properties of simple lipids: hydrolysis (acidic, alkaline and enzymatic); addition reactions; oxidation reactions. Homework exercises. 1. Write a formula of cetyl palmitate wax. 2. Write formulas of palmitoleic, oleic, linoleic, linolenic, arachidonic ac- ids in cis-form. 3. Write the formulas of monoacylglycerol and diacylglycerol in general form. 4. Write the formulas of 1‑oleoyl‑2‑palmitoyl‑3‑linoleoylglycerol, 1‑palmito- leoleoyl‑2,3‑distearoylglycerol, 1‑arachidonoyl‑2‑palmitoyl‑3‑stearoylglycerol. 5. Write the equations of acidic and alkaline hydrolysis of trioleoylglycerol, 1‑oleoyl‑2‑palmitoyl‑3‑stearoylglycerol. 6. Write the equation of iodination of trioleoylglycerol and 1,2‑dioleo- yl‑3‑stearoylglycerol. 7. Write the equation for the hydrogenation of 1,2‑dioleoyl‑3‑stearoylglyc- erol and 1‑oleoyl‑2,3‑dipalmitoylglycerol. Laboratory work. Alkaline hydrolysis (saponification) of fat, properties of soap. Experiment 1. Hydrolysis (saponification) of fats. Place 20 drops of oil and 8 drops of 35% NaOH solution in a small porcelain cup. Stir the mixture until smooth. Then heat the contents of the cup on the spirit lamp with constant stirring. The mass will thicken to form a homogeneous slightly yellowish liquid (soap glue), then it will solidify in the form of loose pieces of soap. Write the equation for the hydrolysis of soap, consisting of a palmitic residue and two residues of stearic acid. Name the resulting products of hydrolysis. Experiment 2. Soap dissolving in water. Transfer the soap obtained in the experiment 1 into a test tube, add 4 ml of distilled water and shake the tube. Then heat the tube on the spirit lamp. How does heating affect the dissolution of soap? What are you observing? Make a conclusion about the dissolution of soap in water. Experiment 3. Formation of insoluble calcium salts of higher fatty acids. Put 5 drops of soap solution in a test tube and add 1 drop of CaCl 2  solution.