scholarly journals Cyclic Dipeptides Formation From Linear Dipeptides Under Potentially Prebiotic Earth Conditions

2021 ◽  
Vol 9 ◽  
Author(s):  
Yeting Guo ◽  
Jianxi Ying ◽  
Dongru Sun ◽  
Yumeng Zhang ◽  
Minyang Zheng ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Origin Of Life ◽  
Chiral Catalysts ◽  
Cyclic Dipeptides ◽  
Peptide Precursors ◽  
The Origin Of Life ◽  
Prebiotic Earth

Cyclic dipeptides (DKPs) are peptide precursors and chiral catalysts in the prebiotic process. This study reports proline-containing DKPs that were spontaneously obtained from linear dipeptides under an aqueous solution. Significantly, the yields of DKPs were affected by the sequence of linear dipeptides and whether the reaction contains trimetaphosphate. These findings provide the possibility that DKPs might play a key role in the origin of life.

scholarly journals The origin of life: the first self-replicating molecules were nucleotides

2019 ◽  
Author(s):  
Ken Ohsaka
Keyword(s):  
Origin Of Life ◽  
Clay Minerals ◽  
The Self ◽  
Rna Molecules ◽  
Simulated Environments ◽  
The Origin Of Life ◽  
Prebiotic Earth ◽  
Self Replication

Difficulties to synthesize RNA nucleotides from their subunits in modern labs under simulated environments leads us to propose a possible process for the synthesis by cross complimentary self-replication with help of clay minerals, which might be operated on prebiotic Earth. Clay minerals are known to be good catalysts and certainly existed on prebiotic Earth. The self-replication of RNA nucleotides (monomers) may be considered as the origin of potential self-replication of some extant RNA polymers, and also the reason for homochirality of RNA molecules.

scholarly journals A carbonate-rich lake solution to the phosphate problem of the origin of life

2019 ◽  
Vol 117 (2) ◽  
pp. 883-888 ◽  
Author(s):  
Jonathan D. Toner ◽  
David C. Catling
Keyword(s):  
Energy Transfer ◽  
Steady State ◽  
Origin Of Life ◽  
Chemical Weathering ◽  
Natural Waters ◽  
Environmental Constraints ◽  
The Origin Of Life ◽  
Prebiotic Syntheses ◽  
Prebiotic Earth ◽  
Low Solubility

Phosphate is central to the origin of life because it is a key component of nucleotides in genetic molecules, phospholipid cell membranes, and energy transfer molecules such as adenosine triphosphate. To incorporate phosphate into biomolecules, prebiotic experiments commonly use molar phosphate concentrations to overcome phosphate’s poor reactivity with organics in water. However, phosphate is generally limited to micromolar levels in the environment because it precipitates with calcium as low-solubility apatite minerals. This disparity between laboratory conditions and environmental constraints is an enigma known as “the phosphate problem.” Here we show that carbonate-rich lakes are a marked exception to phosphate-poor natural waters. In principle, modern carbonate-rich lakes could accumulate up to ∼0.1 molal phosphate under steady-state conditions of evaporation and stream inflow because calcium is sequestered into carbonate minerals. This prevents the loss of dissolved phosphate to apatite precipitation. Even higher phosphate concentrations (>1 molal) can form during evaporation in the absence of inflows. On the prebiotic Earth, carbonate-rich lakes were likely abundant and phosphate-rich relative to the present day because of the lack of microbial phosphate sinks and enhanced chemical weathering of phosphate minerals under relatively CO2-rich atmospheres. Furthermore, the prevailing CO2 conditions would have buffered phosphate-rich brines to moderate pH (pH 6.5 to 9). The accumulation of phosphate and other prebiotic reagents at concentration and pH levels relevant to experimental prebiotic syntheses of key biomolecules is a compelling reason to consider carbonate-rich lakes as plausible settings for the origin of life.

scholarly journals The origin of life: the first self-replicating molecules were nucleotides

2019 ◽  
Author(s):  
Ken Ohsaka
Keyword(s):  
Origin Of Life ◽  
Clay Minerals ◽  
The Self ◽  
Rna Molecules ◽  
Simulated Environments ◽  
The Origin Of Life ◽  
Prebiotic Earth ◽  
Self Replication

Difficulties to synthesize RNA nucleotides from their subunits in modern labs under simulated environments leads us to propose a possible process for the synthesis by cross complimentary self-replication with help of clay minerals, which might be operated on prebiotic Earth. Clay minerals are known to be good catalysts and certainly existed on prebiotic Earth. The self-replication of RNA nucleotides (monomers) may be considered as the origin of potential self-replication of some extant RNA polymers, and also the reason for homochirality of RNA molecules.

scholarly journals The Role of Hydrogen Sulfide in Evolution and the Evolution of Hydrogen Sulfide in Metabolism and Signaling

Physiology ◽  
2016 ◽  
Vol 31 (1) ◽  
pp. 60-72 ◽  
Author(s):  
Kenneth R. Olson ◽  
Karl D. Straub
Keyword(s):  
Energy Source ◽  
Hydrogen Sulfide ◽  
Origin Of Life ◽  
Ambient Oxygen ◽  
The Origin Of Life ◽  
Prebiotic Earth

The chemical versatility of sulfur and its abundance in the prebiotic Earth as reduced sulfide (H2S) implicate this molecule in the origin of life 3.8 billion years ago and also as a major source of energy in the first seven-eighths of evolution. The tremendous increase in ambient oxygen ∼600 million years ago brought an end to H2S as an energy source, and H2S-dependent animals either became extinct, retreated to isolated sulfide niches, or adapted. The first 3 billion years of molecular tinkering were not lost, however, and much of this biochemical armamentarium easily adapted to an oxic environment where it contributes to metabolism and signaling even in humans. This review examines the role of H2S in evolution and the evolution of H2S metabolism and signaling.

Looking to the Rocks: Molecular Clues to the Origin of Life

2008 ◽  
Author(s):  
Susan M. Gaines ◽  
Geoffrey Eglinton ◽  
Jürgen Rullkötter
Keyword(s):  
Origin Of Life ◽  
Organic Compounds ◽  
High Pressures ◽  
Biological Evolution ◽  
Building Blocks ◽  
Apparent Paradox ◽  
Living Things ◽  
The Origin Of Life ◽  
Living Organisms ◽  
Prebiotic Earth

When Geoff started analyzing leaf waxes, he hadn’t consciously been looking for compounds in living organisms that are likely to survive in sediments, attacking his Derbyshire question from its other end, as is now a standard ploy in biomarker studies. But when he returned from the Canaries in 1961, it began to dawn on him that this was, in fact, what he had done. It also became apparent that he was not alone in his curiosity about the fate of organic compounds in things like rocks and tars. In fact, he had some very good company. Two prominent Nobel chemists gave talks in Glasgow that year, both posing fundamental questions about the stuff of life. And both, Geoff found, shared his maverick interest in the organic chemistry of rocks and oils. Sir Robert Robinson sought to resolve the apparent paradox of petroleum, which appeared to have formed from the buried detritus of plants and algae that had been subjected to high pressures and temperatures, and yet also contained organic compounds that were quite different from any known in plants and algae. And Melvin Calvin, who had discovered how CO2 is converted to organic molecules in photosynthesis, talked about the origin of life. Experiments done in the past decade had given new meaning to such questions, by showing that simple organic chemicals could form spontaneously under conditions similar to those that were likely to have prevailed on the early, prebiotic earth. The mystery of life’s origin suddenly seemed approachable, and discussions had shifted from the purely theoretical and philosophical toward the empirical, and from the paleontological to the chemical. On the contemporary earth, life has something of a monopoly on making organic compounds. But if amino acids and sugars, the basic building blocks of living things, were produced by other than living things on the early earth, before the advent of life, then one could imagine the world before photosynthesis, before bacterial chemosynthesis. One could imagine some form of chemical evolution that predated Darwin’s biological evolution and launched the simplest, most primitive of bacteria. And one could look to the oldest rocks for evidence.

The Tempo and mode(S) of Prebiotic Evolution

1997 ◽  
Vol 161 ◽  
pp. 419-429 ◽  
Author(s):  
Antonio Lazcano
Keyword(s):  
Origin Of Life ◽  
Organic Compounds ◽  
Biological Evolution ◽  
Current Evidence ◽  
Early Diversification ◽  
Time Period ◽  
The Galaxy ◽  
History Of ◽  
Widespread Phenomenon ◽  
The Origin Of Life

AbstractDifferent current ideas on the origin of life are critically examined. Comparison of the now fashionable FeS/H2S pyrite-based autotrophic theory of the origin of life with the heterotrophic viewpoint suggest that the later is still the most fertile explanation for the emergence of life. However, the theory of chemical evolution and heterotrophic origins of life requires major updating, which should include the abandonment of the idea that the appearance of life was a slow process involving billions of years. Stability of organic compounds and the genetics of bacteria suggest that the origin and early diversification of life took place in a time period of the order of 10 million years. Current evidence suggest that the abiotic synthesis of organic compounds may be a widespread phenomenon in the Galaxy and may have a deterministic nature. However, the history of the biosphere does not exhibits any obvious trend towards greater complexity or «higher» forms of life. Therefore, the role of contingency in biological evolution should not be understimated in the discussions of the possibilities of life in the Universe.

Photochemical Evolution of Interstellar/Precometary Organic Material

1997 ◽  
Vol 161 ◽  
pp. 23-47 ◽  
Author(s):  
Louis J. Allamandola ◽  
Max P. Bernstein ◽  
Scott A. Sandford
Keyword(s):  
Origin Of Life ◽  
Building Blocks ◽  
Complex Species ◽  
Infrared Observations ◽  
Interstellar Ice ◽  
Polycyclic Aromatic ◽  
Ultraviolet Photolysis ◽  
The Origin Of Life ◽  
Simple Molecules ◽  
Complex Organic

AbstractInfrared observations, combined with realistic laboratory simulations, have revolutionized our understanding of interstellar ice and dust, the building blocks of comets. Since comets are thought to be a major source of the volatiles on the primative earth, their organic inventory is of central importance to questions concerning the origin of life. Ices in molecular clouds contain the very simple molecules H2O, CH3OH, CO, CO2, CH4, H2, and probably some NH3and H2CO, as well as more complex species including nitriles, ketones, and esters. The evidence for these, as well as carbonrich materials such as polycyclic aromatic hydrocarbons (PAHs), microdiamonds, and amorphous carbon is briefly reviewed. This is followed by a detailed summary of interstellar/precometary ice photochemical evolution based on laboratory studies of realistic polar ice analogs. Ultraviolet photolysis of these ices produces H2, H2CO, CO2, CO, CH4, HCO, and the moderately complex organic molecules: CH3CH2OH (ethanol), HC(= O)NH2(formamide), CH3C(= O)NH2(acetamide), R-CN (nitriles), and hexamethylenetetramine (HMT, C6H12N4), as well as more complex species including polyoxymethylene and related species (POMs), amides, and ketones. The ready formation of these organic species from simple starting mixtures, the ice chemistry that ensues when these ices are mildly warmed, plus the observation that the more complex refractory photoproducts show lipid-like behavior and readily self organize into droplets upon exposure to liquid water suggest that comets may have played an important role in the origin of life.

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