Class 11 NEET Biology Biomolecules Questions Part 2

Concept:Levels of protein structure describe the folding and arrangement of polypeptide chains.Key Fact:The alpha-helix is a common secondary structure element formed by hydrogen bonding between backbone amino groups and carbonyl groups.Explanation:Secondary structure refers to local folded patterns like alpha-helices and beta-sheets.Primary structure is simply the linear sequence of amino acids.Tertiary structure is the overall 3D folding of a single polypeptide.Quaternary structure involves assembly of multiple polypeptide subunits.Thus, the alpha-helix belongs to the secondary level of protein organization.Answer:A. Secondary structure