[Abbr. of deoxyribonucleic acid ]
A complex nucleic acid of high molecular weight consisting of nucleotides made of deoxyribose, phosphoric acid, and one of four bases (two purines, adenine [A] and guanine [G], and two pyrimidines, thymine [T] and cytosine [C]). The nucleotides are arranged in a double helix (two long spirals twisting around each other) joined by hydrogen bonds between the complementary base pairs A-T and C-G. Nucleic acid, present in chromosomes of the nuclei of cells, is the chemical basis of heredity and the carrier of genetic information for all organisms except the RNA viruses.



SEE: chromosome; SEE: gene; SEE: RNA; SEE: virus