Which of the following types of chemical bonds are responsible for forming the primary structure of proteins?

Hydrogen bonds are important for stabilizing secondary and tertiary structures of proteins, such as alpha helices and beta sheets, but they do not contribute to the formation of the primary structure. The primary structure is strictly defined by the sequence of amino acids linked by peptide bonds, making hydrogen bonds irrelevant to this specific level of structural organization.

Phosphodiester bonds are found in nucleic acids, linking nucleotides together in DNA and RNA. They are not involved in protein structure. Since proteins are made up of amino acids rather than nucleotides, phosphodiester bonds have no role in the primary structure of proteins.

Disulfide bonds form between the sulfur atoms of cysteine residues and help stabilize the three-dimensional structure of proteins. However, they are not responsible for the primary structure, which is solely defined by the sequence of amino acids linked by peptide bonds. Thus, disulfide bonds contribute to higher-order structures, not the primary structure.