DNA - Deoxyribonucleic acid

DNA nucleic acid, the genetic instructions used in the development and functioning of all known living organisms and some viruses. The main role of DNA molecules is the long-term storage of information. DNA is often compared to a set of patterns or a rule or code, because the necessary instructions to other parts of the cell contains a construct such as proteins and RNA molecules. DNA segments that carry genetic information are called genes, but other DNA sequences for structural purposes, or on the use of genetic information are involved.

Chemically related to DNA consists of two long polymers of simple units, nucleotides, the skeletons of sugars and phosphate groups by ester bonds. These two aspects in opposite directions to each other and therefore anti-parallel. On each sugar is one of four types of molecules called principles. This is the order of these four bases along the spine, the information encoded. This information is collected by the genetic code, which gives the sequence of amino acids in proteins. The code is read by copying stretches of DNA in the corresponding nucleic acid in a process called RNA transcription.

In cells, DNA is organized in long structures called chromosomes. These chromosomes are duplicated before cell division, in a process called DNA replication. Eukaryotes (animals, plants, fungi and protozoa) to store most of their DNA in the nucleus, and some of its DNA into organelles such as mitochondria and chloroplasts. [1] to save the contrast to the prokaryotes (bacteria and archaea) of DNA only in the cytoplasm. In chromosomes, chromatin proteins such as histones compact and organize DNA. These small structures result in interactions between DNA and other proteins that control which DNA fragments are stored.