DNA - deoxyribonucleic acid is, which ensures the preservation and transmission of genetic information.In its structure the encrypted information on the structure of RNA and proteins of the body.Open this structure Swiss I.Mishlerom in 1869.
first real properties of DNA were unknown.It was believed that she was responsible for maintaining the body's phosphorus, and its properties to transmit information were not even aware, because carriers of hereditary information traditionally considered proteins.Only in 1944, after a series of experiments to transform bacteria, it was found that such DNA, and also defines its main function.After 1952, the information about the molecule widened - it became known that she is the main carrier of information about the structure of the genotype (the set of genes in an organism), but at the time of its very structure still does not know the structure of DNA was not transcribed.
Its molecular structure was deciphered in 1953 by James Watson and Francis Crick.They determined that a DNA - the molecule in the form of a double helix consisting of deoxyribose and phosphate groups that bind nitrogen bases - adenine, cytosine, guanine and thymine.
It should be noted that the combination of these foundations is clearly a certain order - adenine binds only with thymine, and guanine with cytosine, which ensures a correct and clear self-replication of the DNA molecule according to the principle of complementarity with one of its subsidiaries spirals.
Such a clear identification of the molecular structure made it possible to better understand what the DNA - the structure, which preserves the genetic code and heredity is the basis of all living organisms, including eukaryotes and some viruses.
genetic code is stored in the form of a specific nucleotide sequence.Thus, each amino acid of the protein encoded by three nucleotides and the sequence of the genes is an acid.
If any changes occur in the structure of DNA, or point mutations.Point mutational changes are in violation of the molecular structure that is easy to detect by biochemical or hybridological analysis.Gene mutations occur when changing alternation of nucleotides, which is the result of processes such as transitions, transversions, insertion or loss of individual base pairs, which violate the functioning and properties of DNA.
If these structural changes lead to a distortion of the important parts of the polypeptide in the organism there are serious violations, which determine not only a violation of organisms, but also their death.For example, mutations can occur even in utero, causing the birth of dead or non-viable children.In addition, such violations are at the heart of many birth defects that can be passed to future generations.
To summarize, we can conclude as to what is DNA - it is an extremely important structure of genetic information, which is the main component of chromosomes.In addition, DNA - acid, which is responsible for carrying hereditary information and the functioning of living organisms.