Nucleic Acids

DNA and RNA are the two kinds of nucleic acid known to biology. Both were originally isolated from within the cell nucleus, which is the origin of the name 'nucleic acid'. Nucleic acids are present in all known cells and viruses, and each carries a specially coded genetic programme containing the detailed, specific instructions needed for an organism's heredity - that is, for building the organism and passing its traits on to offspring. DNA and RNA are both polymers built from repeating monomer units called nucleotides; each nucleotide is composed of three chemical parts - a nitrogenous base, a pentose (five-carbon) sugar, and a phosphate group - whose individual chemistry …