Liaisons hydrogène

A hydrogen bond is a weak electrostatic attraction between molecules. In a polar covalent bond, the hydrogen atom develops a partial positive charge. This allows it to interact with a nearby atom, such as nitrogen, oxygen, or fluorine, that carries a partial negative charge. This interaction is called a hydrogen bond.

Hydrogen bonds are most commonly found between water molecules, but they are also found in biological macromolecules, including DNA base pairs. In these pairs, adenine and thymine form two hydrogen bonds, and cytosine and guanine form three. Together, these bonds provide stability to DNA.

Although each hydrogen bond is weak, many hydrogen bonds acting together create a strong intermolecular attraction and help stabilize molecular structures. They also affect many physical and biological properties, such as water’s high boiling point and protein structure stability.