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49 2. Classification of amino acids (by polarity and charge of the radical, by the number of functional groups, by the structure of the radical, by the presence of additional functional groups, biological classification). 3. Physical properties of amino acids 4. Chemical properties of amino acids (amphotericity, formation of a bipo- lar ion, formation of a complex copper (II) salt, deamination with nitrous acid. 5. Qualitative reactions to amino acids: a general qualitative reaction of the α-amino acids with ninhydrin, a qualitative reaction to the sulfur-containing amino acid cysteine, a qualitative reaction to aromatic amino acids. 6. The most important reactions of amino acids in the human body: deamination, transaminationand decarboxylation. 7. Charges of amino acids in different solution media. Separation of amino acids in an electric field under different solution media. Learn the formulas of the 20 most important α-amino acids. Homework exercises. 1. Write formulas for positively charged, negatively charged, polar uncharged and non-polar amino acids. 2. What electrode will thealanine, glutamic acid, lysinemoves to in the electric field at pH = 6.02? Explainthese processes. 3. What electrode will the alanine, glutamic acid, lysine moves to in the electric field at pH = 3.22? Explain these processes. 4. What electrode will the alanine, glutamic acid, lysinemoves to in the electric field at pH = 9.74? Explain these processes. 5. Write the equations of the formation of a complex salt of glycine, alanine, valine, leucine, phenylalanine with copper hydroxide Cu (OH) 2. 6. Writethe equationsof deamination of glycine, alanine, valine, leucine, phenylalanine with nitrous acid HNO 2. 7. Write the transamination reactions of alanine, valine, aspartic acid, phenylalanine, tyrosine, serine with α-ketoglutaric acid. 8. Write decarboxylation reactions for amino acids according to the schemes given below: a) glycine → methylamine + CO 2 b) alanine →ethylamine + CO 2 c) tryptophan →tryptamine + CO 2 d) tyrosine → tyramine + CO 2