This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
[{'content': 'Which of the following structure is not affected by protein denaturation? \nSelect and explain. \nA. Primary structure, B. Secondary structure, C. Tertiary structure, D. Quaternary structure', 'role': 'user'}, {'content': 'Answer: A \nExplanation: PROTEIN DENATURATION • In quaternary structure denaturation, protein sub-units are dissociated and/or the spatial arrangement of protein subunits is disrupted.\n• Primary structure, such as the sequence of amino acids held together by covalent peptide bonds, is not disrupted by denaturation.\n• In secondary structure, denaturation proteins adopt a random coil as they lose all regular repeating patterns such as alpha-helices and beta-pleated sheets and configuration.\n• Tertiary structure denaturation involves the disruption of:\n1. Covalent interactions between amino acid side- chains (such as disulfide bridges between cysteine groups)\n2. Non-covalent dipole-dipole interactions between polar amino acid side-chains (and the surrounding solvent)\n3. Van der Waals (induced dipole) interactions between nonpolar amino acid side-chains', 'role': 'assistant'}]