THYMINE. Other bases are considered purine base such as Guanine and Adenine. Purine and Pyrimidine forms a complimentary base pairs that is connected to each other by H bonds. There is a rule that states C Pairs with G and A pairs with T in DNA. However there is a difference when we are talking about RNA. In RNA, A will pair with U or Uracil. This are the DNA nucleotide that contains nitrogen, sugar molecule and a phosphate group. In DNA sugar is a deoxyribose which is a five carbon sugar of DNA nucleotides.