Biological Evolution of Dialects of the Genetic Code

2010 ◽  
pp. 50-64
Author(s):  
Sergey Petoukhov ◽  
Matthew He
Keyword(s):  
Amino Acids ◽  
Solar Energy ◽  
Genetic Code ◽  
Molecular Genetic ◽  
Biological Evolution ◽  
Comparative Investigation ◽  
Fundamental Question ◽  
The Earth ◽  
Genetic Systems ◽  
Living Substance

This chapter demonstrates results of a comparative investigation of characteristics of degeneracy of all known dialects of the genetic code. This investigation is conducted on the basis of the results of symmetrological analysis, which were described in Chapter 2, about the division of the set of the 20 amino acids into the two canonical subsets: the subset of the 8 high-degeneracy acids and the subset of the 12 low-degeneracy acids. The existence of numerical and structural invariants in the set of these dialects is shown. The derived results from the comparative investigation permit one to formulate some phenomenological rules of evolution of these dialects. These numeric invariants and parameters of code degeneracy draw attention to the formal connection of this evolution with famous facts of chrono-biology and chrono-medicine. The chronocyclic conception of the functioning of molecular-genetic systems is proposed on this basis. The biophysical basis of this conception provides connection to the genetic code structures with mechanisms of photosynthesis which produce living substance by means of utilization of solar energy. And the solar energy comes cyclically on the surface of the Earth. The revealed numeric invariants of evolution of the genetic code give new approaches to the fundamental question, why do 20 amino acids exist? We will demonstrate new patterns of the genetic code systems.

scholarly journals Astrochemistry as the basics of Astrobiology: from simplest molecules to bioindicatorsonexoplanets surfaces

2018 ◽  
Vol 2 (1) ◽  
pp. 33-64
Author(s):  
A.G. Yeghikyan ◽  
Keyword(s):  
Amino Acids ◽  
Origin Of Life ◽  
Biological Evolution ◽  
Complex Compounds ◽  
Optically Active ◽  
Point Of View ◽  
Heavy Hydrocarbons ◽  
The Earth ◽  
Other Substances ◽  
The Origin Of Life

The problem of the origin of Life is discussed from the astrophysical point of view. Most biologists and geologists up to the present time believe that Life was originated on the Earth in some initial natural chemical pre-reactors, where a mixture of water, ammonia, methane containing species and some other substances, under the influence of an energy source like, e.g. lightning, turned into quite complex compounds such as amino acids and complex hydrocarbons. In fact, under conditions of the primordial Earth, it is not possible to obtain such pre-biological molecules by not-bio-chemical methods, as discussed in this paper. Instead, an astrophysical view of the problem of the origin of Life on the Earth is proposed and it is recalled that the biological evolution on the Earth was preceded by the chemical evolution of complex chemical compounds, mostly under extraterrestrial conditions, where it is only possible to form optically active amino acids, sugars and heavy hydrocarbons necessary for constructing the first pre-biomolecules. Then, according to a widespread point of view, they were brought to Earth by comets and dust between 4.5 and 3.8 billion years ago. Some part of the matter of comets landed unchanged during grazing collisions. Prebiotic complexes on the surface of the planet participate in the formation of a specific cover with a reflective spectrum (or color index), whose characteristic details can be tried to reveal by observation. The most promising bio-indicators at present are optically active amino acids and their derivatives, however, the existing observational capabilities are insufficient to identify them. More promising as (pre)biomarkers are the heavy hydrocarbons discussed in this article, in particular bitumen and isoprene hydrocarbons.

Rendez vous with Saturn's rings

1984 ◽  
Vol 75 ◽  
pp. 743-759 ◽  
Author(s):  
Kerry T. Nock
Keyword(s):  
Solar Energy ◽  
Electric Propulsion ◽  
Power Source ◽  
Propulsion System ◽  
Low Thrust ◽  
Ring Plane ◽  
The Earth ◽  
Total Impulse ◽  
Saturn's Rings

ABSTRACTA mission to rendezvous with the rings of Saturn is studied with regard to science rationale and instrumentation and engineering feasibility and design. Future detailedin situexploration of the rings of Saturn will require spacecraft systems with enormous propulsive capability. NASA is currently studying the critical technologies for just such a system, called Nuclear Electric Propulsion (NEP). Electric propulsion is the only technology which can effectively provide the required total impulse for this demanding mission. Furthermore, the power source must be nuclear because the solar energy reaching Saturn is only 1% of that at the Earth. An important aspect of this mission is the ability of the low thrust propulsion system to continuously boost the spacecraft above the ring plane as it spirals in toward Saturn, thus enabling scientific measurements of ring particles from only a few kilometers.

scholarly journals Transferability of N-terminal mutations of pyrrolysyl-tRNA synthetase in one species to that in another species on unnatural amino acid incorporation efficiency

Amino Acids ◽  
2020 ◽  
Author(s):  
Thomas L. Williams ◽  
Debra J. Iskandar ◽  
Alexander R. Nödling ◽  
Yurong Tan ◽  
Louis Y. P. Luk ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Genetic Code ◽  
Unnatural Amino Acids ◽  
Trna Synthetase ◽  
Unnatural Amino Acid ◽  
Amino Acid Incorporation ◽  
Acid Incorporation ◽  
Genetic Code Expansion ◽  
Incorporation Efficiency

AbstractGenetic code expansion is a powerful technique for site-specific incorporation of an unnatural amino acid into a protein of interest. This technique relies on an orthogonal aminoacyl-tRNA synthetase/tRNA pair and has enabled incorporation of over 100 different unnatural amino acids into ribosomally synthesized proteins in cells. Pyrrolysyl-tRNA synthetase (PylRS) and its cognate tRNA from Methanosarcina species are arguably the most widely used orthogonal pair. Here, we investigated whether beneficial effect in unnatural amino acid incorporation caused by N-terminal mutations in PylRS of one species is transferable to PylRS of another species. It was shown that conserved mutations on the N-terminal domain of MmPylRS improved the unnatural amino acid incorporation efficiency up to five folds. As MbPylRS shares high sequence identity to MmPylRS, and the two homologs are often used interchangeably, we examined incorporation of five unnatural amino acids by four MbPylRS variants at two temperatures. Our results indicate that the beneficial N-terminal mutations in MmPylRS did not improve unnatural amino acid incorporation efficiency by MbPylRS. Knowledge from this work contributes to our understanding of PylRS homologs which are needed to improve the technique of genetic code expansion in the future.

On the Optimization of the Physicochemical Distances between Amino Acids in the Evolution of the Genetic Code

1994 ◽  
Vol 168 (1) ◽  
pp. 43-51 ◽  
Author(s):  
Massimo Di Giulio ◽  
M.Rosaria Capobianco ◽  
Mario Medugno
Keyword(s):  
Amino Acids ◽  
Genetic Code

Gravimetric Method for Calibrating Flow Meter

2014 ◽  
Vol 501-504 ◽  
pp. 2335-2337
Author(s):  
Xi Ming Zhang ◽  
Xue Li
Keyword(s):  
Solar Energy ◽  
Gravimetric Method ◽  
Correction Coefficient ◽  
Flow Meter ◽  
The Earth ◽  
Improve Measurement ◽  
Long Time ◽  
Experimental Errors ◽  
Lower Energy Density ◽  
Test Use

What the earth obtain the energy annually is ten thousand times of the earth energy consumption at present,but the solar energy has a lower energy density on the earth’s surface .solar energy is the main source of all energy The experimental research was conducted for the heating performance utilizing the solar-assisted heat pump experimental platform. Experimental errors will be caused to flow meter by different measured media and long time usage In order to improve measurement precision and reduce the experimental errors, this test use gravimetric method to calibrate the LZB glass rotor meter and MCE08-787 cumulative flow meter of indoors and outdoors pipes. The paper also presents flow correction coefficient to guarantee both the accuracy and reliability of the experimental results.

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