Which of the following interactions primarily stabilize the tertiary structure of a protein?

• A. Only peptide bonds
• B. Phosphodiester bonds
• C. Hydrogen bonds, disulfide bridges, hydrophobic interactions, and ionic bonds
• D. Glycosidic linkages

Answer: (C)

Verified step by step guidance

1. Understand the concept of tertiary structure: The tertiary structure of a protein refers to its three-dimensional shape, which is stabilized by various interactions between the side chains (R groups) of amino acids.
2. Identify the types of interactions involved: Tertiary structure is primarily stabilized by hydrogen bonds, disulfide bridges, hydrophobic interactions, and ionic bonds. These interactions occur between the side chains of amino acids and contribute to the protein's overall stability.
3. Clarify why peptide bonds are not the primary stabilizers: Peptide bonds are covalent bonds that link amino acids together in the primary structure of a protein. While they are essential for forming the protein backbone, they do not play a direct role in stabilizing the tertiary structure.
4. Explain why phosphodiester bonds and glycosidic linkages are irrelevant: Phosphodiester bonds are found in nucleic acids (DNA and RNA), and glycosidic linkages are found in carbohydrates. Neither of these bond types is involved in protein tertiary structure stabilization.
5. Summarize the correct answer: The primary stabilizing interactions for the tertiary structure of a protein are hydrogen bonds, disulfide bridges, hydrophobic interactions, and ionic bonds. These interactions ensure the protein folds into its functional three-dimensional shape.