Which of the following correctly describes the quaternary structure of a protein?

• A. The local folding patterns such as alpha helices and beta sheets.
• B. The arrangement of multiple polypeptide chains into a functional protein complex.
• C. The overall three-dimensional shape of a single polypeptide chain.
• D. The sequence of amino acids in a polypeptide chain.

Answer: (B)

Verified step by step guidance

1. Understand the four levels of protein structure: primary, secondary, tertiary, and quaternary.
2. Primary structure refers to the sequence of amino acids in a polypeptide chain.
3. Secondary structure involves local folding patterns such as alpha helices and beta sheets.
4. Tertiary structure is the overall three-dimensional shape of a single polypeptide chain.
5. Quaternary structure describes the arrangement of multiple polypeptide chains into a functional protein complex.