Final answer:
A hairpin structure within an RNA molecule is stabilized by hydrogen bonds, which form when the RNA folds back on itself to pair complementary nucleotides.
Step-by-step explanation:
A hairpin structure within an RNA molecule is stabilized by hydrogen bonds. This occurs when the RNA folds back on itself and forms intramolecular hydrogen bonds between complementary nucleotides. The peptide bond's rigidity affects the secondary and tertiary structures of proteins. However, in RNA, the hydrogen bonds are not related to the rigidity of peptide bonds but to the pairing between the bases of the nucleotides.
In protein structures, like the α-helix and β-pleated sheets, hydrogen bonds also play a critical role. They create bridges between different regions of the same polypeptide strand or between adjacent polypeptide chains, contributing to the protein's secondary structure. Similarly, hydrogen bonds are crucial in the RNA hairpin structure formation and stabilization.