Physical-Chemical Properties of Amino Acid Solutions

PHYSICAL-CHEMICAL PROPERTIES OF AMINO ACID SOLUTIONS 

Amino acids constitute a particularly important class of bifiinctional compounds the two functional groups in an amino acid are, respectively, basic and acidic, the compounds are amphoteric, and in fact exist as zwit-terions or inner salts. For example, glycine, the simplest amino acid, exists mosdy in the zwitterion form shown first, rather than as aminoacetic acid 

Most of the amino acids are only sparingly soluble in water, as a consequence of the strong intermolecular electrostatic attraction of zwit-terions in the crystal lattice. Exceptions are GLY, ALA, PRO, LYS and ARG, which are quite soluble in water. The water solubility of amino acids is given in Table 2 [5]. All except ASP, GLU and TYR exceed a solubility of 1 g per 100 cm at 25 C. 

CHj(CH,)i VAL, Valine CHjCH(CHj), LEU. Leucine CH(CHj)CjHj ILE, Isoleiicine CHjOH SER, Serine 

CHjCHjSCHj MET, Methionine CHjC Hj PHE, Phenylalanine CHjCjH.OH TYR Tyrosine CHj-CH, 

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II. PHYSICAL-CHEMICAL PROPERTIES OF AMINO ACID SOLUTIONS... 

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