Nucleic acid structures are stabilized by
Nucleic acid structures are stabilized by
Select an option to attempt
Correct Answer: Option B
Explanation
The DNA double helix is stabilised by two types of non-covalent forces: (1) Base stacking (hydrophobic interactions) — the planar aromatic rings of adjacent bases stack on top of each other, minimising contact with water (hydrophobic effect). This contributes ~60–70% of helix stability. (2) Watson-Crick hydrogen bonds — A:T pairs share 2 H-bonds; G:C pairs share 3 H-bonds. These bonds contribute specificity and additional stability. Covalent bonds (phosphodiester backbone) exist within each strand but do not stabilise the double helix between strands. Hydrophilic interactions do not stabilise the helix.