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How do hydrogen bonds help stabilize DNA molecules?

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representations of molecular structure — molecule Several methods of representing a molecule's structure. In Lewis structures, element symbols represent atoms, and dots represent electrons surrounding them. A pair of shared electrons (covalent bond) may also be shown as a single dash. The ball-and-stick model better illustrates the spatial arrangement of the atoms. For aromatic compounds, the Kekulé structure is common, in which each bond is represented by a dash, carbon atoms are implied where two or more lines meet, and hydrogen atoms are usually omitted. Bond-line formulas, similar to the Kekulé structure, are often used for complex nonaromatic organic compounds. Sugars are often drawn as Fischer projections, in which the carbon “backbone” is drawn as a straight vertical line, with carbon atoms implied where horizontal lines intersect the vertical one.

Hydrogen bonds are essential for stabilizing the DNA molecule by connecting the two strands of the double helix. These bonds form between complementary nitrogenous bases—specifically, adenine pairs with thymine, and guanine pairs with cytosine.12

By acting as the "glue" that holds these complementary strands together, hydrogen bonds create the stable helical configuration necessary for the storage and transmission of genetic information. While these interactions are strong enough to maintain the structural integrity of the double helix under normal conditions, they are also sufficiently reversible to allow the strands to separate during biological processes. For instance, heating a DNA solution can break these hydrogen bonds, causing the strands to "melt" or denature, a property that is fundamental to many techniques used in molecular biology to manipulate and study DNA.134