What term describes the three-dimensional shape of a single polypeptide chain?

What term describes the three-dimensional shape of a single polypeptide chain?

• A. Secondary structure
• B. Primary structure
• C. Tertiary structure
• D. Quaternary structure

Answer: (C)

The three-dimensional folding of a single polypeptide chain is called its tertiary structure. This level describes the overall shape that results from interactions among the side chains of amino acids, including hydrophobic clustering, hydrogen bonding, ionic interactions, and covalent disulfide bonds. It sits beyond the primary sequence (the linear order of amino acids) and the secondary elements like alpha helices and beta sheets, and it is distinct from quaternary structure, which involves how multiple polypeptide chains fit together. The tertiary structure is essential for function because it forms the specific arrangement of an active site and other functional regions.

The three-dimensional folding of a single polypeptide chain is called its tertiary structure. This level describes the overall shape that results from interactions among the side chains of amino acids, including hydrophobic clustering, hydrogen bonding, ionic interactions, and covalent disulfide bonds. It sits beyond the primary sequence (the linear order of amino acids) and the secondary elements like alpha helices and beta sheets, and it is distinct from quaternary structure, which involves how multiple polypeptide chains fit together. The tertiary structure is essential for function because it forms the specific arrangement of an active site and other functional regions.