04.06 | 12:19
According to American scientists, the first living cells on Earth contain not only the ribonucleic acid (RNA), and proteins.
«We believe that life on the early Earth was a world of proteins and RNA, and not just the RNA world “, – said Charles Carter of the University of North Carolina (USA).
Recall that today accepted theory of the” RNA world “in which role of proteins and DNA in the first living organisms on the earth played RNA molecule. Today, scientists are trying to replicate the process of the origin of life in the laboratory to understand how there was a transition to the current tandem of DNA and proteins.
The main issue is that the proteins are preserved only in a very small range of basic chemical parameters. Report of at least one leads to the destruction of the protein molecule. The latter feature of proteins was the reason that the scientific world took the model of “RNA world” for the ultimate truth, as it was believed that protein molecules could not exist in the hot early Earth’s oceans.
Charles Carter and his colleague Richard Volfenden nevertheless decided to test whether this is so, learn how to “feel” the amino acids themselves at extreme temperatures. It was found that the difference in the physical properties of the amino acids, their interaction with the nucleotides were identical at 25 degrees Celsius, and at 100.
This result suggests that the proteins might exist in the hot ocean early Earth. Proof of this, scientists have found in the transport RNA molecules that carry amino acids to the center of the assembly of proteins in the cell. It turned out that RNA has two selection systems relevant amino acid, one selects the desired size of the molecules and the other selects those well to repel water. The availability of these systems suggests that the evolution of proteins was in two phases, with the origin of life.
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