The properties of the genetic code and its common DNA system

By the genetic code it is customary to understand such a system of signs denoting the sequential arrangement of nucleotide compounds in DNA and RNA, which corresponds to another sign system displaying the sequence of amino acid compounds in the protein molecule.

It is important!

When scientists managed to study the properties of the genetic code, universality was recognized as one of the main ones. Yes, strange as it may sound, all living organisms unite one, universal, common genetic code. It was formed during a large time interval, and the process ended about 3.5 billion years ago. Therefore, in the structure of the code it is possible to trace the traces of its evolution, from the moment of origin to the present day.

When it is said about the sequence of the arrangement of elements in the genetic code, it is meant that it is far from chaotic, but has a strictly defined order. And this, too, largely determines the properties of the genetic code. This is equivalent to the arrangement of letters and syllables in words. It's worth breaking the usual order, and most of what we read on book or newspaper pages will turn into a ridiculous abracadabra.

Basic properties of the genetic code

Usually the code carries in itself any information, encrypted in a special way. In order to decipher the information of the genetic code, it is necessary to know the distinctive features.

So, the basic properties of the genetic code are:

• The tripletness;
• Degeneracy or redundancy;
• Uniqueness;
• continuity;
• The above universality.

Let us dwell in more detail on each property.

1. The triplet

This is when three nucleotide compounds form a sequential chain within the nucleic acid molecule (ie DNA or RNA). As a result, a triplet or codon connection is created. This codon encodes one of the amino acids, its location in the peptide chain.

There are codons (they are codewords!) According to their sequence of connection and the type of those nitrogenous compounds (nucleotides) that make up their composition.

In genetics it is customary to allocate 64 codon types. They can form combinations of four types of nucleotides of 3 in each. This is equivalent to raising the number 4 to the third power. Thus, the formation of 64 nucleotide combinations is possible.

2. Redundancy of the genetic code

This property is traced when several codons are required to encrypt one amino acid, usually within 2-6. And only amino acids methionine and tryptophan can be encoded using a single triplet.

3. Uniqueness

It is included in the properties of the genetic code as an indicator of healthy gene heredity. For example, a good state of blood, normal hemoglobin can tell doctors who is in the sixth place in the chain triplet GAA. It is he who carries information about hemoglobin, and he also encodes glutamic acid. And if a person is sick with anemia, one of the nucleotides is replaced by another letter of the code - U, which is the signal of the disease.

4. Continuity

When writing this property of a genetic code, it should be remembered that codons, as links in a chain, are not located at a distance, but in direct proximity, one after another in the nucleic acid chain, and this chain does not terminate - it has no beginning or end.

5. Universality

One should never forget that everything on earth is united by a common genetic code. Therefore, in primacy and man, in an insect and a bird, a hundred-year-old baobab, and similarly triple-cut grasses, identical amino acids are encoded by the same triplets.

It is in the genes that the basic information about the properties of this or that organism is laid down, a kind of program that the organism receives as a legacy from those who lived earlier and which exists as a genetic code.