Question

The secondary structure of protein is determined by

• A. co-ordinate bond
• B. covalent bond
• C. ionic bond
• D. hydrogen bond

Hint:

Alpha helix and beta sheet are held by hydrogen bonds.

Answer 1

The Correct Option is D

Step 1: Match each level
Primary: peptide (covalent) bonds. Secondary: hydrogen bonds. Tertiary: S-S, ionic, hydrophobic. Option (D).

Final Answer:
Option (D). \[ \boxed{\text{(D)}} \]