Practice question

Question

An alpha helix formed by 30 residues is stabilized by 25 backbone hydrogen bonds in its folded state. Assume that the average energy of a hydrogen bond is ~10 kJ/mol, and the disruption in the peptide resonance causes a partial loss of 205 kJ/mol per peptide bond. Assume that the folding and unfolding process only changes peptide resonance stabilization partially and the loss of hydrogen bonding upon unfolding (ignore side-chain interactions and entropy losses). Which one of the following options represents the correct magnitude of the net energetic difference between the folded and unfolded state of the helix?