Q&A for How to Build a DNA Model

Watson and Crick used Rosalind Franklin's x-ray diffraction data to determine that DNA contains two strands of nucleotides that appeared to be helical in nature. They also showed that one strand of DNA acted as a template for the other.

Four different nucleotides make up DNA: adenine, guanine, thymine, and cytosine. Each nucleotide contains a phosphate group, a sugar, and a nitrogenous base. The phosphate groups serve as the "backbone" of DNA while complementary base-pairing between nucleotides (adenine pairs with thymine, guanine pairs with cytosine) form the inside of the molecule.

The nitrogenous bases connect to the sugar part of the backbone (deoxyribose). the sugars are connected by the phosphate groups. so the nitrogenous bases should be attached to the middle of the sugar in your model.

The nitrogenous bases are attached to the sugar with a glycosidic bond. The phosphate group links two sugars to each other with a phosphodiester bond.