This animation explores the chemical components and bonds of the nucleotides that make up DNA.

As shown in the animation, DNA is a polymer of units called nucleotides, which contain deoxyribose sugars and nitrogenous bases. The nucleotides are linked in a directional manner via phosphodiester bonds between their sugars. The nitrogenous bases also form hydrogen bonds with one another based on predictable base pairing rules: adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G).

Depending on students’ background, it may be helpful to pause the animation at various points to discuss different parts of DNA’s structure.