DNA Structure

DNA stands for deoxyribonucleic acid which is a structure of sugar, phosphate and a base combined into a complex double helix. The two strands in the helix are complementary to each other, which means that each DNA strand contains the template information for synthesis of a new copy of the other strand.

The building blocks of DNA are the 5-carbon sugar deoxyribose linked together by phosphodiester bonds forming two strands of sugar-phosphate backbones on the outside of the double helix. Each ribose also binds one of four alternative bases: adenine (A), guanine (G), cytosine (C) or thymine (T).The opposing strands are held together by basepairing between the two strands: G is always paired with C by three hydrogen bonds and A is always paired with T by two hydrogen bonds.