Abiotic synthes is of amino acids by proton irradiation of simulated primitive earth atmospheres

1989 ◽  
Vol 19 (3-5) ◽  
pp. 233-234
Author(s):  
Kensei Kobayashi ◽  
Masahiko Tsuchiya ◽  
Tairo Oshima ◽  
Hiroshi Yanagawa
Keyword(s):  
Amino Acids ◽  
Proton Irradiation ◽  
Primitive Earth

Abiotic synthesis of amino acids and imidazole by proton irradiation of simulated primitive earth atmospheres

1990 ◽  
Vol 20 (2) ◽  
pp. 99-109 ◽  
Author(s):  
Kensei Kobayashi ◽  
Masahiko Tsuchiya ◽  
Tairo Oshima ◽  
Hiroshi Yanagawa
Keyword(s):  
Amino Acids ◽  
Proton Irradiation ◽  
Primitive Earth ◽  
Abiotic Synthesis

Laboratory simulation of UV irradiation from the Sun on amino acids. I: irradiation of tyrosine

2007 ◽  
Vol 6 (2) ◽  
pp. 123-129 ◽  
Author(s):  
F. Scappini ◽  
F. Casadei ◽  
R. Zamboni ◽  
S. Monti ◽  
P. Giorgianni ◽  
...  
Keyword(s):  
Amino Acids ◽  
Uv Irradiation ◽  
Degradation Products ◽  
Building Blocks ◽  
Laboratory Simulation ◽  
The Sun ◽  
Primitive Earth ◽  
Laboratory Results ◽  
Building Capability ◽  
Primordial Life

AbstractThe effects of ultraviolet (UV) irradiation on water solutions of tyrosine (HO—C6H4—CH2—CHNH2—COOH) have been investigated using a Xe lamp in the region 200–800 nm. This is a step in laboratory simulation towards reproducing the action of the Solar radiation on the building blocks of life, specifically α-amino acids, in the primitive Earth anoxic conditions. Results are presented showing the photostability of tyrosine against different UV doses. Degradation products partly maintain life building capability and partly do not. A tendency towards structure complexification was observed. The analysis of the irradiated tyrosine solutions was conducted using various spectroscopic and analytic techniques. The laboratory results are discussed in the light of a primordial life-emerging scenario.

scholarly journals Long-Wavelength Ultraviolet Photoproduction of Amino Acids on the Primitive Earth

Science ◽  
1971 ◽  
Vol 173 (3995) ◽  
pp. 417-420 ◽  
Author(s):  
C. Sagan ◽  
B. N. Khare
Keyword(s):  
Amino Acids ◽  
Primitive Earth ◽  
Long Wavelength

scholarly journals Homochirality May Not Be a Prerequisite for Protein Structure and Function: A Computational Model Investigation of Prebiotic Peptides

2020 ◽  
Author(s):  
Jianxun Shen ◽  
Pauline M. Schwartz ◽  
Carl Barratt
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Hierarchical Cluster ◽  
Building Blocks ◽  
Beta Sheets ◽  
Folding Energy ◽  
Primitive Earth ◽  
C Terminus ◽  
Significant Difference ◽  
Prebiotic Amino Acids

On the primitive Earth, both L- and D-amino acids would have been present. However, only L-amino acids are essential blocks to construct proteins in modern life. To study the relative stability of homochiral and heterochiral peptides, a variety of computational methods were employed. 10 prebiotic amino acids (Gly, Ala, Asp, Glu, Ile, Leu, Pro, Ser, Thr, and Val) were previously determined by multiple previous meteorite, spark discharge, and hydrothermal vent studies. We focused on what had been reported as primary early Earth polypeptide analogs: 1ARK, 1PPT, 1ZFI, and 2LZE. Tripeptide composed of only Asp, Ser, and Val exemplified that different positions (i.e., N-terminus, C-terminus, and middle) made a difference in minimal folding energy of peptides, while the classification of amino acid (hydrophobic, acidic, or hydroxylic) did not show significant difference. Hierarchical cluster analysis for dipeptides with all possible combinations of the proposed 10 prebiotic amino acids and their D-amino acid substituted derivatives generated five clusters. Prebiotic polypeptides were built up to test the significance of molecular fluctuations, secondary structure occupancies, and folding energy differences based on these clusters. Most interestingly, among 129 residues, mutation sensitivity profiles presented that the ratio of more stable to less stable to equally stable D-amino acids was about 1:1:1. In conclusion, some combinations of a mixture of L- and D-amino acids can act as essential building blocks of life. Peptides with α-helices, long β-sheets, and long loops are usually less sensitive to D-amino acid replacements in comparison to short β-sheets.

Comets and Life on the Primitive Earth

1997 ◽  
Vol 161 ◽  
pp. 97-120 ◽  
Author(s):  
Juan Orò ◽  
Cristiano B. Cosmovici
Keyword(s):  
Amino Acids ◽  
Prebiotic Synthesis ◽  
External Source ◽  
Primitive Earth ◽  
Molecular Precursors ◽  
The Earth ◽  
Biochemical Compounds ◽  
Comet Halley ◽  
The Impact ◽  
Cometary Origin

AbstractComets may have contributed substantial amounts of water, volatiles and organic precursors such as HCN for the synthesis of biochemical compounds on the primitive Earth. This suggestion followed closely the prebiotic synthesis of adenine, purines and amino acids from HCN. Recent studies on the terrestrial heavy noble gases provide evidence that comets are the principal external source of Earth’s volatiles. During the encounter of comet Halley strong jets of CN, C2, C3and NH2were measured from Earth observatories, and by spacecraft mass spectrometry HCN, formaldehyde, adenine and many other organic compounds were detected, except amino acids. Obviously the latter require liquid water for their formation. Therefore upon capture of comets by the Earth, and melting of the frozen water, the synthesis of most biochemical compounds could take place readily. The detection of water, HCN and other organics of cometary origin after the impact of Comet SL-9 with Jupiter demonstrated the capability of survival of these molecules even after catastrophic events. Thus on the Earth HCN could be converted into purines, cyanacetylene, after hydration and condensation with urea, into pyrimidines, and formaldehyde into monosaccharides. In the presence of phosphates, which have been detected in cometary IDPs, nucleotides could also be synthesized. In conclusion, comets probably provided the necessary molecular precursors for the generation of life on the Earth.

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