Describe the structure of DNA

Nucleotides make up DNA. Nucleotides themselves are made up of a phosphate, sugar and base.

They bases are: Adenine (A), Thymine (T), Cytosine (C), Guanosine (G). 

A is bonded to T. C is bonded to G. The bases are bonded by phosphodiester bonds. 

The remaining phosphate and sugar make up the backbone of the DNA, forming two strands on either side of the bases.

These strands then wind around eachother to form the 'double helix' structure.