The α-helix is a type of secondary structure in proteins. While the provided context mentions that proteins are polymers of α-amino acids linked by peptide bonds (primary structure) and describes secondary structure including right-handed helices, it does not explicitly state the bonding type that stabilizes the α-helix. However, the standard NCERT answer is hydrogen bonding, which forms between the C=O group of one amino acid and the N-H group of another amino acid in the polypeptide chain, creating the helical structure.