Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
Secondary level refers to the organization or folding patterns that occur within segments (alpha helices or beta pleated sheets) of polypeptide chains. It is responsible for the local three-dimensional structure of a protein.
Related terms
Primary level of protein structure: The linear sequence or order of amino acids within a polypeptide chain.
Tertiary level of protein structure: The overall three-dimensional shape of a protein, formed by interactions between different regions (secondary structures) of the polypeptide chain.
Quaternary level of protein structure: The arrangement and interaction of multiple polypeptide chains to form a functional protein complex.
"Secondary level of protein structure" also found in: