What are the subunits of nucleic acids?
The DNA is a pattern made up of four different nucleotides. Each nucleotide consists of a sugar (deoxyribose) in the middle of a phosphate group and a nitrogenous base .
There are two classes of bases. Two are purines (double-ringed structures) and two are pyrimidines (single-ringed structures). The four bases in DNA's alphabet are:
adenine (A) - a purine
cytosine(C) - a pyrimidine
guanine (G) - a purine
thymine (T) - a pyrimidine
In both DNA and RNA there are four major bases. However, RNA has the first three plus uracil. The substitution of uracil for thymine as a base material constitutes the chief chemical difference between RNA and DNA. RNA also has ribose as it's sugar instead of deoxyribose.