Question

The secondary structure of a protein refers to

• A. fixed configuration of the polypeptide backbone
• B. $\alpha$-helical backbone
• C. hydrophobic interactions
• D. sequence of $\alpha$ - amino acids.

Answer 1

Answer: (B)

The secondary structure of a protein refers to local folded structures that form within a polypeptide due to interactions between atoms of the backbone. The most common types of secondary structures are the $\alpha$ helix and the $\beta$ pleated sheet. Both structures are held in shape by hydrogen bonds, which form between the carbonyl $O$ of one amino acid and the amino $H$ of another.