DNA(Deoxyribonucleic acid) consist of 2 polynucleotides wrapping around each other(double helix),a strand of polynucleotideis linked together with nucleotides by condensation.Each nucleotide is composed ofa phosphate group ,a base (guanine ,cytosine ,adenine or thymine) and a five carbon sugar(deoxyribose). 所以,DNA唔係由protein組成架. |