scholarly journals Nature's electrochemical flow reactors?: Alkaline hydrothermal vents and the origins of life

2014 ◽  
Vol 36 (6) ◽  
pp. 4-8
Author(s):  
Barry Herschy
Keyword(s):  
Hydrothermal Vents ◽  
Fundamental Problem ◽  
Origins Of Life ◽  
Dynamic Nature ◽  
Flow Reactors ◽  
Scientific Debate ◽  
Chemical Systems ◽  
The Earth ◽  
Emergence Of Life ◽  
Alkaline Hydrothermal Vents

Understanding the evolution and beginnings of biochemistry is a fundamental problem which needs to be addressed in origins of life research. The development of highly complex chemical systems from simple inorganic beginnings is difficult to comprehend and has resulted in much heated scientific debate. The debate is further fuelled by the fact we know very little about conditions present on the early Earth at the time life began. Owing to the highly dynamic nature of the Earth, the geological record for the earliest period of Earth's history when life began is practically non-existent. Without geochemical indicators, we have no idea about the composition of the atmosphere or oceans, when or how much water was present on the Earth's surface or the chemical inventory present before the emergence of life. There has been much speculation and argument around all of these points about what could be acceptably deemed ‘prebiotically plausible’ environmental conditions. We do know that life started somewhere, but the where, when and how may only be solved by a process of elimination by experimentation.

scholarly journals Membraneless polyester microdroplets as primordial compartments at the origins of life

2019 ◽  
Vol 116 (32) ◽  
pp. 15830-15835 ◽  
Author(s):  
Tony Z. Jia ◽  
Kuhan Chandru ◽  
Yayoi Hongo ◽  
Rehana Afrin ◽  
Tomohiro Usui ◽  
...  
Keyword(s):  
Chemical Evolution ◽  
Protein Function ◽  
Common Ancestor ◽  
Fluorescent Dyes ◽  
Origins Of Life ◽  
Last Universal Common Ancestor ◽  
Biomolecular Systems ◽  
Chemical Systems ◽  
Universal Common Ancestor ◽  
Emergence Of Life

Compartmentalization was likely essential for primitive chemical systems during the emergence of life, both for preventing leakage of important components, i.e., genetic materials, and for enhancing chemical reactions. Although life as we know it uses lipid bilayer-based compartments, the diversity of prebiotic chemistry may have enabled primitive living systems to start from other types of boundary systems. Here, we demonstrate membraneless compartmentalization based on prebiotically available organic compounds, α-hydroxy acids (αHAs), which are generally coproduced along with α-amino acids in prebiotic settings. Facile polymerization of αHAs provides a model pathway for the assembly of combinatorially diverse primitive compartments on early Earth. We characterized membraneless microdroplets generated from homo- and heteropolyesters synthesized from drying solutions of αHAs endowed with various side chains. These compartments can preferentially and differentially segregate and compartmentalize fluorescent dyes and fluorescently tagged RNA, providing readily available compartments that could have facilitated chemical evolution by protecting, exchanging, and encapsulating primitive components. Protein function within and RNA function in the presence of certain droplets is also preserved, suggesting the potential relevance of such droplets to various origins of life models. As a lipid amphiphile can also assemble around certain droplets, this further shows the droplets’ potential compatibility with and scaffolding ability for nascent biomolecular systems that could have coexisted in complex chemical systems. These model compartments could have been more accessible in a “messy” prebiotic environment, enabling the localization of a variety of protometabolic and replication processes that could be subjected to further chemical evolution before the advent of the Last Universal Common Ancestor.

scholarly journals Green Rust: The Simple Organizing ‘Seed’ of All Life?  

2018 ◽  
Author(s):  
Michael J Russell
Keyword(s):  
Hydrothermal Vents ◽  
Green Rust ◽  
Hydrothermal Fluids ◽  
Iron Sulfides ◽  
Banded Iron Formations ◽  
Variable Valence ◽  
Present Evidence ◽  
The Earth ◽  
Iron Formations ◽  
Emergence Of Life

Korenaga and coworkers present evidence to suggest that 4.3 billion years ago the Earth’s mantle was dry and water filled the ocean to twice its present volume.[2] CO2 was constantly exhaled during the mafic to ultramafic volcanic activity associated with magmatic plumes that produced the thick, dense and relatively stable oceanic crust. In that setting two distinct major types of sub-marine hydrothermal vents were active: ~400 °C acidic springs whose effluents bore vast quantities of iron into the ocean, and ~120 °C, highly alkaline and reduced vents exhaling from the cooler, serpentinizing crust at some distance from the heads of the plumes. When encountering the alkaline effluents, the iron from the plume head vents precipitated out forming mounds likely surrounded by voluminous exhalative deposits similar to the banded iron formations known from the Archean. These mounds and the surrounding sediments likely comprising nanocrysts of the variable valence FeII/FeIII oxyhydroxide, green rust. The precipitation of green rust, along with subsidiary iron sulfides and minor concentrations of Ni, Co and Mo in the environment at the alkaline springs may have established both the key bio-syntonic disequilibria, and the means to properly make use of them – those needed to drive the essential inanimate-to-animate transitions that launched life. In the submarine alkaline vent model for the emergence of life specifically it is first suggested that the redox-flexible green rust microcrysts spontaneously formed precipitated barriers to the complete mixing of carbonic ocean and alkaline hydrothermal fluids, barriers that created and maintained steep ionic disequilibria; and second, that the hydrous interlayers of green rust acted as 'engines' that were powered by those ionic disequilibria and drove essential endergonic reactions. There, aided by sulfides and trace elements acting as catalytic promoters and electron transfer agents, nitrate could be reduced to ammonia and carbon dioxide to formate, while methane may have been oxidized to methyl and formyl groups. Acetate and higher carboxylic acids could then have been produced from these C1 molecules and aminated to amino acids, and thence oligomerized to offer peptide nests to phosphate and iron sulfides and secreted to form primitive amyloid-bounded structures, leading conceivably to protocells.

scholarly journals Conjecture and hypothesis: The importance of reality checks

2017 ◽  
Vol 13 ◽  
pp. 620-624 ◽  
Author(s):  
David Deamer
Keyword(s):  
Origin Of Life ◽  
Fresh Water ◽  
Hydrothermal Vents ◽  
Origins Of Life ◽  
Weight Of Evidence ◽  
The Earth ◽  
Alternative Hypotheses ◽  
The Origin Of Life ◽  
The Difference ◽  
Hydrothermal Fields

In origins of life research, it is important to understand the difference between conjecture and hypothesis. This commentary explores the difference and recommends alternative hypotheses as a way to advance our understanding of how life can begin on the Earth and other habitable planets. As an example of how this approach can be used, two conditions have been proposed for sites conducive to the origin of life: hydrothermal vents in salty seawater, and fresh water hydrothermal fields associated with volcanic landmasses. These are considered as alternative hypotheses and the accumulating weight of evidence for each site is described and analyzed.

scholarly journals Experimental Approaches for Testing the Hypothesis of the Emergence of Life at Submarine Alkaline Vents

Life ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 777
Author(s):  
Thiago Altair ◽  
Luiz G. F. Borges ◽  
Douglas Galante ◽  
Hamilton Varela
Keyword(s):  
Origin Of Life ◽  
Experimental Work ◽  
Hydrothermal Vents ◽  
Key Concepts ◽  
Experimental Approaches ◽  
Experimental Works ◽  
The Origin Of Life ◽  
Chemical Gardens ◽  
Emergence Of Life ◽  
Alkaline Hydrothermal Vents

Since the pioneering experimental work performed by Urey and Miller around 70 years ago, several experimental works have been developed for approaching the question of the origin of life based on very few well-constructed hypotheses. In recent years, attention has been drawn to the so-called alkaline hydrothermal vents model (AHV model) for the emergence of life. Since the first works, perspectives from complexity sciences, bioenergetics and thermodynamics have been incorporated into the model. Consequently, a high number of experimental works from the model using several tools have been developed. In this review, we present the key concepts that provide a background for the AHV model and then analyze the experimental approaches that were motivated by it. Experimental tools based on hydrothermal reactors, microfluidics and chemical gardens were used for simulating the environments of early AHVs on the Hadean Earth (~4.0 Ga). In addition, it is noteworthy that several works used techniques from electrochemistry to investigate phenomena in the vent–ocean interface for early AHVs. Their results provided important parameters and details that are used for the evaluation of the plausibility of the AHV model, and for the enhancement of it.

scholarly journals Autocatalytic and oscillatory reaction networks that form guanidines and products of their cyclization

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Alexander I. Novichkov ◽  
Anton I. Hanopolskyi ◽  
Xiaoming Miao ◽  
Linda J. W. Shimon ◽  
Yael Diskin-Posner ◽  
...  
Keyword(s):  
Chemical Cues ◽  
Native Chemical Ligation ◽  
Reaction Networks ◽  
Oscillatory Reaction ◽  
Experimental Conditions ◽  
Chemical Ligation ◽  
Chemical Systems ◽  
Life On Earth ◽  
Emergence Of Life ◽  
Equilibrium Chemical

AbstractAutocatalytic and oscillatory networks of organic reactions are important for designing life-inspired materials and for better understanding the emergence of life on Earth; however, the diversity of the chemistries of these reactions is limited. In this work, we present the thiol-assisted formation of guanidines, which has a mechanism analogous to that of native chemical ligation. Using this reaction, we designed autocatalytic and oscillatory reaction networks that form substituted guanidines from thiouronium salts. The thiouronium salt-based oscillator show good stability of oscillations within a broad range of experimental conditions. By using nitrile-containing starting materials, we constructed an oscillator where the concentration of a bicyclic derivative of dihydropyrimidine oscillates. Moreover, the mixed thioester and thiouronium salt-based oscillator show unique responsiveness to chemical cues. The reactions developed in this work expand our toolbox for designing out-of-equilibrium chemical systems and link autocatalytic and oscillatory chemistry to the synthesis of guanidinium derivatives and the products of their transformations including analogs of nucleobases.

scholarly journals Investigating Prebiotic Protocells for a Comprehensive Understanding of the Origins of Life: A Prebiotic Systems Chemistry Perspective

Life ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 49 ◽  
Author(s):  
Augustin Lopez ◽  
Michele Fiore
Keyword(s):  
Thin Films ◽  
Synthetic Biology ◽  
Chemical Compounds ◽  
Origins Of Life ◽  
Supramolecular Systems ◽  
Comprehensive Understanding ◽  
Giant Vesicles ◽  
Relevant Concept ◽  
Systems Chemistry ◽  
Emergence Of Life

Protocells are supramolecular systems commonly used for numerous applications, such as the formation of self-evolvable systems, in systems chemistry and synthetic biology. Certain types of protocells imitate plausible prebiotic compartments, such as giant vesicles, that are formed with the hydration of thin films of amphiphiles. These constructs can be studied to address the emergence of life from a non-living chemical network. They are useful tools since they offer the possibility to understand the mechanisms underlying any living cellular system: Its formation, its metabolism, its replication and its evolution. Protocells allow the investigation of the synergies occurring in a web of chemical compounds. This cooperation can explain the transition between chemical (inanimate) and biological systems (living) due to the discoveries of emerging properties. The aim of this review is to provide an overview of relevant concept in prebiotic protocell research.

scholarly journals Nitrate radical generation via continuous generation of dinitrogen pentoxide in a laminar flow reactor coupled to an oxidation flow reactor

2020 ◽  
Author(s):  
Andrew T. Lambe ◽  
Ezra C. Wood ◽  
Jordan E. Krechmer ◽  
Francesca Majluf ◽  
Leah R. Williams ◽  
...  
Keyword(s):  
Laminar Flow ◽  
Flow Reactor ◽  
Nitrate Radical ◽  
Peroxy Radicals ◽  
Flow Reactors ◽  
Dinitrogen Pentoxide ◽  
Oxidative Aging ◽  
Chemical Systems ◽  
Alkyl Radicals ◽  
Aerosol Mass

Abstract. Oxidation flow reactors (OFRs) are an emerging tool for studying the formation and oxidative aging of organic aerosols and other applications. The majority of OFR studies to date involved generation of the hydroxyl radical (OH) to mimic daytime oxidative aging processes. On the other hand, use of the nitrate radical (NO3) in modern OFRs to mimic nighttime oxidative aging processes has been limited due to the complexity of conventional techniques that are used to generate NO3. Here, we present a new method that uses a laminar flow reactor (LFR) to continuously generate dinitrogen pentoxide (N2O5) in the gas phase at room temperature from the NO2 + O3 and NO2 + NO3 reactions. The N2O5 is then injected into a dark Potential Aerosol Mass OFR and decomposes to generate NO3; hereafter, this method is referred to as OFR-iN2O5 (i = injected). To assess the applicability of the OFR-iN2O5 method towards different chemical systems, we present experimental and model characterization of the integrated NO3 exposure, NO3:O3, NO2:NO3, and NO2:O2 as a function of LFR and OFR conditions. These parameters were used to investigate the fate of representative organic peroxy radicals (RO2) and aromatic alkyl radicals generated from volatile organic compound (VOC) + NO3 reactions, and VOCs that are reactive towards both O3 and NO3. Finally, we demonstrate the OFR-iN2O5 method by generating and characterizing secondary organic aerosol from the β-pinene + NO3 reaction.

scholarly journals Intrinsic concentration cycles and high ion fluxes in self-assembled precipitate membranes

2019 ◽  
Vol 9 (6) ◽  
pp. 20190064 ◽  
Author(s):  
Yang Ding ◽  
Julyan H. E. Cartwright ◽  
Silvana S. S. Cardoso
Keyword(s):  
Cell Membrane ◽  
Fluid Mechanics ◽  
Ion Channel ◽  
Hydrothermal Vents ◽  
Biological Processes ◽  
Biological Cell ◽  
Osmotic Flow ◽  
Building Components ◽  
Self Assembled ◽  
Emergence Of Life

Concentration cycles are important for bonding of basic molecular building components at the emergence of life. We demonstrate that oscillations occur intrinsically in precipitation reactions when coupled with fluid mechanics in self-assembled precipitate membranes, such as at submarine hydrothermal vents. We show that, moreover, the flow of ions across one pore in such a prebiotic membrane is larger than that across one ion channel in a modern biological cell membrane, suggesting that proto-biological processes could be sustained by osmotic flow in a less efficient prebiotic environment. Oscillations in nanoreactors at hydrothermal vents may be just right for these warm little pores to be the cradle of life.

scholarly journals Green Rust: The Simple Organizing ‘Seed’ of All Life?

Life ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 35 ◽  
Author(s):  
Michael Russell
Keyword(s):  
Carbon Dioxide ◽  
Hydrothermal Vents ◽  
Green Rust ◽  
Iron Sulfides ◽  
Banded Iron Formations ◽  
Variable Valence ◽  
Earth’S Mantle ◽  
Nickel Cobalt ◽  
Iron Formations ◽  
Emergence Of Life

Korenaga and coworkers presented evidence to suggest that the Earth’s mantle was dry and water filled the ocean to twice its present volume 4.3 billion years ago. Carbon dioxide was constantly exhaled during the mafic to ultramafic volcanic activity associated with magmatic plumes that produced the thick, dense, and relatively stable oceanic crust. In that setting, two distinct and major types of sub-marine hydrothermal vents were active: ~400 °C acidic springs, whose effluents bore vast quantities of iron into the ocean, and ~120 °C, highly alkaline, and reduced vents exhaling from the cooler, serpentinizing crust some distance from the heads of the plumes. When encountering the alkaline effluents, the iron from the plume head vents precipitated out, forming mounds likely surrounded by voluminous exhalative deposits similar to the banded iron formations known from the Archean. These mounds and the surrounding sediments, comprised micro or nano-crysts of the variable valence FeII/FeIII oxyhydroxide known as green rust. The precipitation of green rust, along with subsidiary iron sulfides and minor concentrations of nickel, cobalt, and molybdenum in the environment at the alkaline springs, may have established both the key bio-syntonic disequilibria and the means to properly make use of them—the elements needed to effect the essential inanimate-to-animate transitions that launched life. Specifically, in the submarine alkaline vent model for the emergence of life, it is first suggested that the redox-flexible green rust micro- and nano-crysts spontaneously precipitated to form barriers to the complete mixing of carbonic ocean and alkaline hydrothermal fluids. These barriers created and maintained steep ionic disequilibria. Second, the hydrous interlayers of green rust acted as engines that were powered by those ionic disequilibria and drove essential endergonic reactions. There, aided by sulfides and trace elements acting as catalytic promoters and electron transfer agents, nitrate could be reduced to ammonia and carbon dioxide to formate, while methane may have been oxidized to methyl and formyl groups. Acetate and higher carboxylic acids could then have been produced from these C1 molecules and aminated to amino acids, and thence oligomerized to offer peptide nests to phosphate and iron sulfides, and secreted to form primitive amyloid-bounded structures, leading conceivably to protocells.

General discussion after session V

1988 ◽  
Vol 325 (1587) ◽  
pp. 611-618 ◽  
Keyword(s):  
Origin Of Life ◽  
Time Perspective ◽  
Applied Mathematics ◽  
Building Blocks ◽  
Living Systems ◽  
Organic Chemical ◽  
General Terms ◽  
The Earth ◽  
The Origin Of Life ◽  
Emergence Of Life

N. C. Wickramasinghe ( Department of Applied Mathematics and Astronomy, University College, Cardiff, U. K. ). The question of the origin of life is, of course, one of the most important scientific questions and it is also one of the most difficult. One is inevitably faced here with a situation where there are very few empirical facts of direct relevance and perhaps no facts relating to the actual transition from organic material to material that can even remotely be described as living. The time perspective of events that relate to this problem has already been presented by Dr Chang. Uncertainty still persists as to the actual first moment of the origin or the emergence of life on the Earth. At some time between 3800 and 3300 Ma BP the first microscopic living systems seem to have emerged. There is a definite moment in time corresponding to a sudden appearance of cellular-type living systems. Now, traditionally the evolution of carbonaceous compounds which led to the emergence of life on Earth could be divided into three principal steps and I shall just remind you what those steps are. The first step is the production of chemical building blocks that lead to the origin of the organic molecules necessary as a prerequisite for the evolution of life. Step two can be described in general terms as prebiotic evolution, the arrangement of these chemical units into some kind of sequence of precursor systems that come almost up to life but not quite; and then stage three is the early biological evolution which actually effects the transition from proto-cellular organic-type forms into truly cellular living systems. The transition is from organic chemistry, prebiotic chemistry to biochemistry. Those are the three principal stages that have been defined by traditional workers in the field, the people who, as Dr Chang said, have had the courage to make these queries and attempt to answer them. Ever since the classic experiments where organic materials were synthesized in the laboratory a few decades back, it was thought that the first step, the production of organic chemical units, is important for the origin of life on the Earth, and that this had to take place in some location on the Earth itself.

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