Nucleic acid

Nucleic acids, polynucleotide, is a high-molecular biologically important compounds; are an essential part of every cell of a living organism.
Nucleic acids are the polymer of nucleotides. Each nucleotide consists of a purine or pyrimidine bases, carbohydrate balance - ribose or deoxyribose and the balance of phosphoric acid. Nucleotides together in long chains through the remains of phosphoric acid. All nucleic acids are divided into two main types:
1) ribonucleic acid (RNA), which as of carbohydrates contain ribose, and as the bases adenine (a), guanine (G), cytosine (C) and uracil (U);
2) deoxyribonucleic acid (DNA), which, instead of ribose contain the deoxyribose and uracil instead of thymine. In addition, nucleic acids contain a relatively small number of so-called minor (rare) bases, which, as a rule, derived from the above. RNA molecule is usually a single polynucleotide chain, often rolled into fancy shapes. DNA has a double helix structure in which the complementary bases (adenine with thymine, and guanine with cytosine) paired with each other. The principle of complementarity is very important for playback of nucleic acids in the body. Thanks to this principle on the matrix DNA is synthesized complementary polynucleotide chain DNA (DNA biosynthesis - replication) or RNA (in the process of synthesis of RNA transcription).
The synthesis of RNA occurs under the action of the enzyme RNA polymerase from nucleosidase with the removal of pyrophosphate and connection of nucleotides in the chain, complementary DNA matrix. DNA replication is similarly under the action of DNA polymerase from deoxyribonucleosides.
The DNA in the nucleus of cells has a molecular weight of reaching tens and hundreds of millions, and is in the form of deoxyribonucleotides - complexes with proteins, mainly the main character - histones and Protamine. RNA is divided into ribosomal RNA which is over 50% of the material ribosomes, transfer RNA, a relatively small molecular weight, carrying in the process of protein synthesis amino acids to the ribosome, and the messenger RNA that carries biological information from DNA to protein synthesis - the ribosome. As ribosomes and complexes of the messenger RNA to proteins - informality - are a natural ribonucleoprotein (see Nucleoproteins).
Nucleic acids provide storage, transmission and reproduction of biological information, because of the specific structure of nucleic acids, which consists in a unique sequence of nucleotide residues in polynucleotide chain, causes the transmission of hereditary characteristics, and synthesis in the body of specific, individual proteins (see). Cm. also, Genetics, Heredity.