The
basic building-block of life. Each strand of dna is a made up of chemical
units called nucleotides.
Strands are twisted into a double-helix shape. Each nucleotide
consists of a sugar, a phosphate, and one of four nitrogen-containing
fragments called bases.
The order of bases is
the dna sequence.
This sequence
contains the genetic instructions required to create a particular organism
(see genes).
DNA
molecules are long chains consisting of four kinds
of nucleotides;
the order of these nucleotides
encodes the information needed to construct proteinmolecules. These in turn make up much of the molecular machinery of the cell. DNA is the genetic material of cells. (See also RNA.)
Acronym
for deoxyribonucleic acid,
usually 2'-deoxy-5'-ribonucleic acid.
The double-stranded DNA molecule
carries the genetic information, which is encoded in a sequence of base
pairs (adenine and thymine, guanine and cytosin).