Nucleic Acids

Abstract

DNA consists of two antiparallel complementary base-paired strands.  DNA is composed of four different types of bases: the purines adenine and guanine (composed of two-ringed structures) and the pyrimidines cytosine and thymine (single-ringed structures) The complementary strands of DNA allow one strand to be used as a template for replication.  Similarly, one strand of DNA is used as a template for the synthesis of RNA in transcription. The double helical DNA is a stable molecule; several important intermolecular forces are involved in maintaining its stability.  The sequence of RNA is translated into protein; thus the amino acid sequence of a protein is prescribed by the sequence of bases in the DNA.  The amino acid sequence of a protein is an important determinant of protein structure, which is linked to the function of the protein.  Thus the structure of the DNA specifies the characteristics of an organism.