DNA:

The genetic material of organisms is made up of nucleic acids. There are two types of nucleic acids namely Deoxyribonucleic Acid ( DNA) and Ribonucleic Acid (RNA). In most organisms DNA forms the genetic material, while some viruses contain only RNA, which forms the sole genetic material. DNA is a macromolecule and it has a high molecular weight.

Genes are made up of DNA and they are located on the chromosome. Genes are always present on the chromosome at specific sites. DNA is the genetic material of the cell. It carries information in a coded form from cell to cell and from parents to offspring. The combination of a nitrogenous base and a pentose sugar forms what is called a nucleoside.

The addition of phosphate groups to the nucleoside gives rise to nucleotide. DNA is a long linear polymer of nucleotides. DNA is responsible for expression of genetic characters. The genetic information flows from DNA to RNA and from RNA to protein. The concepts constitute the central dogma of molecular biology. The information contained in DNA and in RNA is based on 4 nucleotides. These four nucleotides carry the genetic code which is read in groups of three nucleotides.


Protein synthesis occurs in three different steps. The process by which an enzyme system converts the genetic information of a segment of DNA or template DNA into an RNA strand with a base sequence complementary to one of the DNA strands is called Transcription