We prove experimentally that for any biopolymers (proteins and nucleic acids), the process of thermal denaturation in aqueous medium is characterized by change of the heat capacity regardless a unique spatial structures of different conformations. Absolute values and sign of Delta C-p=C-p,C- denatured-C-p,C- native, depends primarily on conformational peculiarities of macromolecules and concrete mechanisms of interaction of water molecules with biopolymers chains - interaction is very clearly found to be of critical importance for the stability of the spatial structure of any biopolymers in aqueous medium.