The macromolecular system where denaturation takes place, is considered from a molecular thermodynamic point of view as a convolution of a grand canonical ensemble, gce and a canonical ensemble ce. The former corresponds to the solute, the latter to the solvent. The properties of this system can be represented by a convoluted partition function obtained by the product of a grand canonical partition function Z(N), and a canonical partition function, zeta(W). If the experimental equilibrium constant, K-den = [D-hyd]/[N] is substituted for Z(N) and [W](nW) for zeta(W), the convoluted partition function is K-0 = K-den [W](nW), where [W] is the concentration of the solvent in the bulk and n(W) is the number of water molecules involved in the reaction. According to this model, by calculating the derivative partial derivative In K-den/partial derivative(1/T), values of the denaturation enthalpy Delta H-den should be obtained which are a linear function of the absolute temperature. The slope of the straight line Delta H-den = f(T) is dependent upon n(W). The The apparent isobaric heat capacity, C-p,C-app of the solute is calculated by double mixed derivation of In Z(N) with respect to In[W](-nW) and In T. By integration between two temperatures, as in DSC experiments, the apparent isobaric heat capacity yields the apparent enthalpy Delta H-den of the denaturation process.