Overview of the Structure of DNA Deoxyribonucleic Acid (DNA) is gets its name because it contains deoxyribose (a five-sided sugar). The picture on the right shows part of a DNA molecule. As you can see, the molecule is made up of two strands that are held together by hydrogen bonds.  Each strand of DNA consists of a large number of nucleotides. Each nucleotide is made up of a deoxyribose, a phosphate group and a nitrogenous base. There are 4 kinds of nitrogenous bases, Thymine (T), Cytosine (C), Adenine (A), and Guanine (G). In the double stranded DNA, A always pairs with T and C always pairs with G. This is called complementary base pairing.  Don't think that the DNA is linear molecule, in reality, it is the two strands wound around each other to form a double helix. Relating Topics - Transcription - Translation		Picture of a DNA double helix. The green and yellow lines are the nitrogenous bases, and the red pentagons are the sugar backbone. A drawing version of DNA double helix.