During protein denaturation, which types of bonds or interactions are primarily disrupted?

• A. Peptide (amide) bonds
• B. Hydrogen bonds and hydrophobic interactions
• C. Phosphodiester bonds
• D. Glycosidic bonds

Answer: (B)

Verified step by step guidance

1. Understand the concept of protein denaturation: Protein denaturation refers to the process where a protein loses its native three-dimensional structure due to external stress, such as heat, pH changes, or chemical agents, without breaking its primary structure (sequence of amino acids).
2. Identify the types of bonds and interactions involved in protein structure: Proteins have several levels of structure (primary, secondary, tertiary, and quaternary). Secondary structures (e.g., alpha-helices and beta-sheets) are stabilized by hydrogen bonds, while tertiary and quaternary structures are maintained by hydrophobic interactions, ionic bonds, disulfide bridges, and van der Waals forces.
3. Determine which bonds are disrupted during denaturation: Protein denaturation primarily affects the secondary, tertiary, and quaternary structures by disrupting hydrogen bonds and hydrophobic interactions. These interactions are responsible for maintaining the protein's folded shape.
4. Clarify why peptide (amide) bonds are not disrupted: Peptide bonds form the primary structure of the protein and are covalent bonds between amino acids. Denaturation does not break these bonds, as it only affects non-covalent interactions and the overall folding of the protein.
5. Explain why phosphodiester and glycosidic bonds are irrelevant: Phosphodiester bonds are found in nucleic acids (DNA and RNA), and glycosidic bonds are found in carbohydrates. These bonds are not part of protein structure and are unrelated to protein denaturation.