Tertiary structure is not directly dependent on tertiary structure is not directly dependent on bonds between sulfur atoms hydrophobic interactions hydrogen bonds ionic bonds peptide bonds

The answer is:

Peptides bonds

The explanation:

when:

Tertiary structure is achieved when a protein folds into a compact, three-dimensional shape stabilized by interactions between side-chain R groups of amino acids .  

-And  peptides are short chains of amino acid monomers linked by peptide (amide) bonds. The covalent chemical bonds are formed when the carboxyl group of one amino acid reacts with the amino group of another.

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer