nucleic acid

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Any of a group of complex compounds found in all living cells and viruses, composed of purines, pyrimidines, carbohydrates, and phosphoric acid. Nucleic acids in the form of DNA and RNA control cellular function and heredity.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Chem., Biochem., Genetics) A natural or synthetic polymer consisting of chains of ribonucleotide or deoxyribonucleotide units.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun biochemistry, genetics Any acidic, chainlike biological macromolecule consisting of multiply repeat units of phosphoric acid, sugar and purine and pyrimidine bases; they are involved in the preservation, replication and expression of hereditary information in every living cell

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun (biochemistry) any of various macromolecules composed of nucleotide chains that are vital constituents of all living cells