Question

Each of the hydrogen bonds in an α-helixα-helix or a β-pleatedβ-pleated sheet is weak relative to a covalent bond, but the large number of hydrogen bonds in these secondary structures makes them what?

Answer 1

Despite individual hydrogen bonds being weak, when numerous such bonds are present in α-helix and β-pleated sheet protein structures, they collectively provide significant stability to these secondary structures.

Step-by-step explanation:

The α-helix and β-pleated sheet are essential secondary structures of proteins, deriving their stability from hydrogen bonds between carbonyl and amino groups in the peptide backbone. While each hydrogen bond is weak compared to a covalent bond, these secondary structures are made robust because of the large number of hydrogen bonds that collectively contribute to their stability.

In an α-helix, these bonds form between every fourth amino acid causing a twist in the chain. In contrast, β-pleated sheets form from hydrogen bonds between atoms on the polypeptide chain's backbone, resulting in pleated segments that align parallel or antiparallel to each other.