nucleic acid

Complex organic acid made up of a long chain of nucleotides, present in the nucleus and sometimes the cytoplasm of the living cell and in viruses. The two types, known as DNA (deoxyribonucleic acid) and RNA (ribonucleic acid), form the basis of heredity. The nucleotides are made up of a sugar (deoxyribose or ribose), a phosphate group, and one of four purine or pyrimidine bases. In protein genes, the order of the bases along the nucleic acid strand contains the information that can be translated into an amino acid sequence according to the genetic code.