In terms of macromolecules, needed and utilized by organisms to carry out essential metabolic chemical reactions and for maintaining structure would be Lipids.
Lipid based molecules or Fats tend to store the most energy, as breaking chemical bonds connecting fatty acid chains of long hydrocarbons releases quite a bit of energy.
I believe the primary structure will be preserved. The secondary level of proteins is defined by patterns of hydrogen bonds between the main chain peptide groups. Therefore distorting the Hydrogen bonds disrupts the secondary structures. The primary structure on the other hand is not affected by disruption of the hydrogen bond since these structures refers to the sequences of amino acids in the polypeptide chains that are joined by the peptide bonds.