Structure of Nucleotide

 Nucleotide, basic structural unit of nucleic acid is made up of three things
 1) Pentose sugar    2) Nitrogenous bases     3) Phosphate group
  Pentose sugar :- pentose is a 5 carbon monosaccharide sugar. DNA has deoxyribose sugar while RNA
   has ribose sugar.
  Here are the structural formulas of deoxyribose and ribose sugar
                                                      deoxyribose (C5H10O4)                ribose (C5H10O5)

  Nitrogenous bases: There are two
categories of bases Purine(adenine and guanine) Pyrimidine(cytosine and thymine) in DNA while uracil replaces thymine in RNA.
        Here are the structural formulas of nitrogenous bases

    

Phosphate group : nucleic acid is acidic in nature due to the presence of phosphoric acid (H3PO4). It forms ester linkage with OH group of pentose sugar.
        structural formula of phosphoric acid

                             the structural formula of one nucleotide is given below

                                             *****************************************
     Types of Nucleotides :
      Following are the types of nucleotides
      Mono nucleotide or adenocine mono phosphate: that nucleotide which has one phosphate group is
       called mono nucleotide or adenocine mono phosphate.
      Di nucleotide or adenosine diphosphate : that nucleotide which has two phosphate groups.
      Tri nucleotide or adenosine triphosphate:  that nucleotide which has three phosphate groups.
      Poly nucleotide:that nucleotide which has more than three phosphate groups or combination of many 
       nucleotides.

Discovery of Nucleic acid

Nucleic acid was discovered by Swiss biochemist, Friedrich Miescher in 1869 from the nuclei of pus cells.
Nucleic acid is present in all living organisms right from virus to man.
Nucleic acid is the polymer of monomers called nucleotides, regarded the structural units of nucleic acid. These nucleotides are linked to each other by ester linkage. It is called Nucleic acid because it was isolated from nuclei and the term nucleic acid was given by Kossel in 1919.