Describe the structure of DNA

DNA is made up of two anti-parallel strands running in opposite directions. It is made up of individual monomers called nucleotides which in turn contain: a sugar (deoxyribose), a base (A, G, C or T), and phosphate group. The sugars and the phosphates bond together resulting in a phosphodiester bond giving rise to the sugar phosphate backbone down one side of the molecule. The four bases are adenine, cytosine, guanine and thymine and form hydrogen-bonds in pairs, A to T and C to G. This is how the two strands stick together. The sequence of bases is what determines the genetic code for the cell.