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May 17, 2017

How life was begun? – Part III

And here comes the final chapter…

Step 4

Since the UV energy is supplied only during the day, night metastable probiont disintegrated, and each morning were born anew. After the third stage of structural and functional organization is so complicated that they have not had time to fully recover during the daylight hours. This is the next evolutionary constraint, which could overcome the organisms that live around the clock, which means having a night power supply.

In living cells there are enzymatic systems of oxidative phosphorylation, not dependent of lighting. They produce macroergs molecules (ATP, etc.), Using chemical energy derived from the partial oxidation of various organic compounds. It is known that without enzymes synthesized by the matrix, they do not work and oxidative phosphorylation impossible. Therefore, the transition to clock probionts life depended on the appearance of the matrix synthesis of polypeptides, enzyme source.

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In the third stage of abiogenesis probionts we have already formed the molecular system of non-matrix synthesis of polypeptides composed of nucleoprotein complexes, substrate-amino acids and relatively macroergs. There were transcription system – synthesis of RNA on DNA arrays. To start the matrix synthesis of polypeptides lacked the main thing – the genetic code. In fact, for his appearance it needed a small but fundamentally important innovation – the conversion of existing nucleoprotein complexes with non-specific affinity for amino acids to specialized tRNA, endowed with active centers with selective affinity with respect to different types of amino acids.

Selective binding of the amino acid polypeptide samples at the polymerization can continue for millions of years without a significant impact on the evolution of probionts. But as soon as this first synthesized by enzymes capable of directing the energy from the oxidation of any organic compounds on the phosphorylation i.e. for the production of ATP and other macroergs, the genetic code and matrix synthesis of acquired selective value. Probionts room got power, turned into a living organism. The main criterion for selection was the quality and quantity of synthesized polypeptides, their inclusion in various biocatalytic processes. It can be assumed that a first synthesized the first enzyme that catalyzes the oxidation of only one existing in organic compound conjugated to the transfer of inorganic phosphate to ADP. One is allowed probionts not decay at night. By the time when the stocks were depleted of organic raw materials, the arsenal of polypeptides synthesized by a matrix has grown considerably. Some of them were included in the ribosome, mRNA and tRNA, whereby increased accuracy and efficiency of biosynthetic polypeptides themselves. Of the other polypeptides to form new enzymes for the oxidative phosphorylation system, lengthening its catalytic chain. This allowed living organisms to obtain chemical energy of many organic compounds aquatic environment.

The first genetic code was much simpler modern. It provides only a rough encoding of certain amino acids, but it affected the properties of the synthesized polypeptides. Probably the primary of the ribosome, which began matrix synthesis of polypeptides were globules of nucleoprotein complexes in which the codon-anticodon matching the mRNA and tRNA controlled energy transfer in their paired sites. Possibly, the same processes are common to all energy and ribosomes may be identified experimentally.

Hour electricity supply networks was the start hypercyclic catalytic reactions by which improvement of one of the subsystems of the cell contributes to the modernization of other subsystems. Hypercycles ensure a rapid increase in the genetic material, the matrix generalization process, increase the arsenal of enzymes. Formed system enzymatic biosynthesis of amino acids, pigments, polysaccharides … There cytoplasmic membrane, complete ribosome, etc. Live cells were shifted from the UV-dependent phosphorylation of photosynthesis in the visible range and settled depth reservoirs devoid of UV light, and after accumulation of atmospheric oxygen, ultraviolet absorbing and land.

The process of the origin of life consisted of four interrelated steps. In the first three parameters probionts strictly determined by environmental conditions, changes under the influence of probionts. In the fourth formed living cells capable of adapting to different environments. Cells were enzymatic mechanisms respond to external stimuli by which they alter their metabolism and control the movement of the cell walls, flagella or other mobile elements. The cells of different organisms differ response spectrum.

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