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43 5. Write a scheme of reactions of interaction of bile acid with glycine with the formation of glycocholic, glycodeoxycholic and glycohenodeoxycholic acid. Laboratory work. Emulsifying properties of soap, phospholipids and bile acids. Pour 1–2 drops of vegetable oilin four test tubes. Add 2–3 ml of distilled water to each test tube and mix the contents of the tubes. Leave the first test tube for monitoring. Add 5–6 drops of soap solutionin the second test tube, 5–6 drops of raw egg yolk (contains lecithin)in the third, 5–6 drops of bile (con- tains bile acids)in the fourth. Shake the test tubes for 0.5 minutes. Observe the changes in the test tubes, explain the observed phenomena. Draw a scheme of emulsification of fats under the influence of bile acids. Makeconclusions. LESSON 20. CHEMISTRY OF MONOSOCHARIDES Required basic level of knowledge. Structure and properties of polyhydric alcohols. Structure and properties of aldehydes and ketones. Structure, production and properties of esters. The reaction of aldehydes (ketones) with alcohols to form hemiacetals. Qualitative reactions to aldehyde group (silver mirror reaction, reduction of copper (II) hydroxide and formation of copper oxide (I)). Questions for the preparation for the lesson. 1. Monosaccharides. Definition. Examples. Physical properties of monosac- charides. 2. Classification of monosaccharides: • by the number of carbon atoms, • according to the functional group, • by belonging to the D‑ and L‑series, • on the structure of the cycle, • on the position of hemiacetal hydroxyl. 3. Products of oxidation and reduction of monosaccharides on the example of glucose. 4. Derivatives of monosaccharides (phospho derivatives, amino derivatives, N‑acetylamino derivatives). 5. Qualitative reactions to monosaccharides (glucose, fructose). Homework exercises. 1. Write formulas of glycerol aldehyde, phosphodioxi aceton, erythrose in an open form (Fisher’s formulas).