CODING OF INFORMATION

From Big Medical Encyclopedia

CODING OF INFORMATION — process of transformation of any messages (information) to code combinations, each of which represents set (usually the sequence) elementary symbols in the form of letters, figures, impulses etc. To. and. provides one-to-one correspondence between messages and their code designations. To. and. is the cornerstone of implementation of the genetic program, transfer of nervous impulses and is one of obligatory elements of normal life activity of organisms (see. Genetic code , Nervous impulse ). To. and. it is widely used in technology of communication, computer facilities etc.

The code can be set in the form of the table or analytically in the form of the formula displaying the rule of formation of the used (resolved) combinations and if it is necessary, then and the rule of compliance between messages and their code designations. Set of various letters or physical. educations, e.g. the nucleotides used as symbols of a code is called the alphabet of a code. The code is called binary (binary) if for formation of combinations two symbols which are conditionally designated by O and 1 are used always. If symbols more than two, each of them is designated letters, and the code is called multiletter.

The quantity of letters in one code combination is called length or word length of a code (e.g., the combination 110001 belongs to a binary code of length six). Uniform codes in which all combinations have identical length are most often used. The code can be and uneven.

The symbol in a difficult code can be considered a code combination of nek-ry simpler code; e.g., the nucleotide can be considered as a symbol of a code of a gene though the nucleotide represents a code combination, in a cut as symbols serve simpler educations (the symbolical designations of chemical elements in total making this chemical connection).

Codes differ not only with the alphabet and length, but also the rule of formation of the used code combinations. Partial use of combinations increases noise immunity of a code. In technology of data transmission the codes allowing not only to find, but also to correct an error that is reached by increase in length of a code are developed (e.g., introduction of the special adjusting symbols). The requirements to noise immunity are higher, the more it is required additional symbols in a code.

By transfer of the decimal numbers reflecting, e.g., results of measurement often use binary codes.

To. and. in live organisms it is carried out on the basis of not binary codes that allows to receive bigger number of combinations with the same length of a code. In particular, in the genetic device of a mother cell information on all biochemical, and morfol, the organizations of an organism is coded. The first part of a code is realized in the form of the sequence of nitrogen bases of molecules DNA and provides a possibility of synthesis of all of connections, necessary for life activity of an organism. In morfol, structures of each combination of generations of cells the second part of a code — the rule of interaction between cells providing further development (growth, a differentiation) is concluded, a cut represents a peculiar key for «reading» of the first part of a code and serves as the determined program of interaction developed in the course of evolution.



Bibliography: Shout F. A genetic code, in book: Structure and functions of a cell, the lane with English, under the editorship of G. M. Frank, page 9, M., 1964; Kuzmini. Century and the Cedar at with V. A. Bases of the theory of information and coding, Kiev, 1977, bibliogr.

G. A. Shastova.

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