The Factors of the Classification of Protein Amino Acids

In this work it is shown that three pairs of the factors appear to be the key, i.e. main factors of a natural classification of protein amino acids, i.e. canonical amino acids within the amino acid (genetic) code. First pair: the factors of the habit (habitus) of an amino acid molecule (size and polarity). Second pair: the factors of the association (type of the amino acid – enzyme reactivity and degree of the hydrophobicity– hydrophilicity of an amino acid molecule). Third pair: the factors of the dissociation (degree of the aciditybasicity, over acidic COOH group and degree of the basicity–acidity over the basic NH2 group). As a result of the influence and interdependence of all six factors (measured through correspondent valid parameters) it appears still one natural classification into polar and non-polar amino acids, where polar amino acids possess negative and non-polar, the positive values of hydropathy index.