Question

Proteins are found to have two different types of secondary structures viz. α-helix and β-pleated sheet structure. α-helix structure of protein is stabilised by : 

(i) Peptide bonds (ii) van der Waals forces (iii) Hydrogen bonds (iv) Dipole-dipole interactions

Answer 1

(iii), Hint : In α-helix, hydrogen bonds are present between –NH group of one amino acid residue to the >C= O group of another aminoacid residue.