Final answer:
The difficulty in disrupting a DNA double helix arises from the collective strength of millions of hydrogen bonds, along with van der Waals interactions between the stacked base pairs, which together create a stable DNA molecule despite the relative weakness of individual hydrogen bonds and stacking forces.
Step-by-step explanation:
While hydrogen bonds and stacking forces that hold a DNA double helix together are individually weak, it is the cumulative effect of millions of these bonds that confers stability to the DNA molecule.
These bonds collectively create a strong and stable structure that requires a significant amount of energy to disrupt.
Each nucleotide base forms hydrogen bonds with its complementary base on the opposing DNA strand, contributing to the overall stability of the double helix. Additionally, the base pairs stack on top of each other, which stabilizes the DNA molecule through van der Waals interactions.
Importance of Hydrogen Bonding in DNA Stability
According to the Watson-Crick model, the double helix of DNA is assembled and stabilized by hydrogen bonding between specific matching "bases".
This precise alignment of hydrogen bonds is crucial for the stability of the double helix and ensures the correct alignment of the corresponding base pairs.
It is noteworthy that although a hydrogen bond is weaker than a covalent bond, the sheer number of hydrogen bonds in a DNA molecule adds considerable strength to its overall structure.