Double Helix (structure of DNA)

The DNA double helix is like a twisted ladder, where two strands of molecules wind around each other. These strands are made of sugar and phosphate groups, with rungs composed of pairs of nitrogen bases (adenine, thymine, cytosine, and guanine). The bases pair specifically—A with T, and C with G—holding the strands together. This elegant structure allows DNA to store genetic information securely, replicate accurately, and guide the production of proteins essential for life. The double helix’s shape was famously discovered by Watson and Crick in 1953.