Question

Which feature correctly distinguishes secondary from tertiary structure of protein?

• A. Secondary structure is established mainly by side chain interaction
• B. Tertiary structure is determined primarily by hydrogen bonds within peptide backbone
• C. Secondary structure involves local folding pattern such as \(\alpha\)-helices and \(\beta\)-sheet
• D. Tertiary structure refers only to the arrangement of multiple polypeptide chain

Hint:

Secondary structure means local patterns like \(\alpha\)-helix and \(\beta\)-sheet, while tertiary structure means overall 3D folding of one polypeptide chain.

Answer 1

The Correct Option is C

Concept:
Protein structure has different levels: primary, secondary, tertiary, and quaternary.

Step 1: Understand secondary structure.
Secondary structure refers to local folding patterns in the polypeptide chain. Examples include: \[ \alpha\text{-helix} \] and \[ \beta\text{-sheet} \]

Step 2: Understand tertiary structure.
Tertiary structure is the overall three-dimensional folding of a single polypeptide chain. It depends on side-chain interactions such as hydrophobic interactions, ionic bonds, hydrogen bonds, and disulfide bonds.

Step 3: Check option (C).
Option (C) correctly states that secondary structure involves local folding patterns such as \(\alpha\)-helices and \(\beta\)-sheets. \[ \therefore \text{Correct Answer is (C)} \]