What type of bonds are primarily responsible for the secondary structure's formation?

The secondary structure of proteins is primarily stabilized by hydrogen bonds. Within a protein, these hydrogen bonds form between the backbone amide hydrogen of one amino acid and the carbonyl oxygen of another amino acid, influencing the protein's folding and overall shape. This allows for the formation of structures such as alpha helices and beta sheets, which are critical for the protein's function.

While covalent bonds, ionic bonds, and disulfide bonds can play important roles in the overall stability of proteins or in specific conditions, they do not primarily dictate the secondary structure itself. Covalent bonds are fundamental for linking amino acids together into a polypeptide chain, ionic bonds may contribute to tertiary structure stability, and disulfide bonds are important for maintaining the integrity of protein structure but are more relevant to the tertiary or quaternary levels rather than the secondary structure.