Explain the properties of amino acids (molecular weight, pK values, pI, Hydropathy index).

Molecular weight : the sum of the atomic weights of the constituent atoms pI: The characteristic pH at which the net electric charge is zero Hydropathy index: values reflect the free energy (DG ) of transfer of the amino acid side chain from a hydrophobic solvent to water. Pka: refers to the equilibrium between the protonated positive nitrogen and deprotonated neutral nitrogen.