ino acids are classifed as ionic or non-ionic, polar or nonpolar. Cysteine and cystine (containing sulphide and disulphide bonds)رare responsible for creating covalent bonds. Hydrogen bonds are created by nonionic polar amino acids, such as threonine, histidine or glutamine. Ionic polar amino acids, glutamic acid, arginine and lysine are responsible for ionic influences. In the case of non-polar amino acids (methionine, proline or phenylalanine) the influences are non-polar [6]