This equation and the data in Table confirm our earlier conclusion from the analysis of Table that the dominant role in the enthalpy of DNA denaturation is the disruption of hydrogen bonds. Five-component analysis reveals details of this mechanism related to nonsymmetrical electron-donor and electron-acceptor properties of two components (DNA and denaturant) with different roles. Thus, our data above and the data of authors show that both the enthalpy and the entropy contribute to the orientation effect as part of the DNA denaturation process. This effect usually takes place as a result of two permanent dipole-dipole interactions. The connection of the orientation and induction cohesive components to such electrostatic parameters as dipole moment, polarizability, and ionization potential has been discussed by Gardon, Keller, Karger, and Snyder 19 and Munafo, Buchman, Ho, and Kesselring. Parameter δ o of the five-component cohesion parameter set is related to δ p from the three-component cohesion parameter set. Comparing equations 22 and 41 leads to the conclusion that