Molecular computer graphics representation of the DNA (deoxyribonucleic acid) molecule, showing its double helix structure. DNA is comprised of two strands of nucleotides linked together in single file. The two stands are knitted together by base- pairing across adjacent nucleotides and coiled into a helix. A nucleotide contains the sugar deoxyribose & one of four organic baes: thymine, adenine, cytosine, & guanine. The former two pair only with each other as do the latter. The genetic information is determined by the arrangement of these pairs along the molecule.