What level of protein structure describes the spatial location of every atom in a protein?

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

Answer: (C)

Verified step by step guidance

1. Understand the four levels of protein structure: primary, secondary, tertiary, and quaternary.
2. The primary structure refers to the sequence of amino acids in a polypeptide chain.
3. The secondary structure involves local folding into structures like alpha-helices and beta-sheets, stabilized by hydrogen bonds.
4. The tertiary structure describes the overall 3D shape of a single polypeptide chain, including the spatial arrangement of all its atoms.
5. The quaternary structure refers to the spatial arrangement of multiple polypeptide chains in a protein complex, if applicable.