DNA

DNA (Deoxyribonucleic acid) is a nucleic acid that serves as the "master molecule" of organic life. The DNA molecules are made up of two intertwined chains of simpler molecules called bases, assembled on rails of sugar and phosphate molecules like rungs on a ladder.

Four different kinds of molecules form the rungs of the DNA ladder: adenine, thymine, guanine, and cytosine, which are typically referred to by their first letters, A, T, G, and C. In the DNA molecule, A always pairs with T, and G always pairs with C. DNA molecules replicate by "unravelling" their rails. Each rail keeps its associated base. Complementary bases (A for T, G for C) attach to the free bases until two new strands of DNA are created.

The blueprint for a living organism, it encodes amino acids for polypeptides which form proteins, which, when properly sequenced, form cellular pathways that together form the physical structure and anatomical characteristics of an organic lifeform.