Structure of DNA and RNA

The sequence of bases along with the DNA and RNA chain makes its primary structure that controls the particular properties of the nucleic acid. An RNA molecule is typically a single chain of ribose-containing nucleotides. DNA particle is a long and highly complex, double helix, ladder, spirally twisted type structure. The two polynucleotide chains or strands are connected by hydrogen bonding among the nitrogenous base molecules of their nucleotide monomers. Adenine or purine all time links with thymine or pyrimidine with the help of two hydrogen bonds and guanine (purine) along with cytosine (pyrimidine) with the help of three hydrogen bonds. Therefore, the two threads expand in reverse directions, that is, are antiparallel and complimentary.