Question

Which type of interactions are responsible for making the $\alpha$-helix structure stable?

• A. Peptide bonds between $—NH_{2}$ and $—CO$ groups of adjacent carbon chains.
• B. Hydrogen bonds between $—NH$ of amino acid in one turn with $—CO$ of amino acid to adjacent turn.
• C. $—OH$ group of one amino acid with $—CO$ group of other amino acid on the turn.
• D. Hydrogen bonds between adjacent amino acids.

Answer 1

Answer: (B)

$α$-helix structures are held in shape by hydrogen bonds, which form between the carbonyl $O$ of one amino acid and the amino $H$ of another amino acid which make it stable.