DOCSLIB.ORG

The Origin of Life—Out of the Blue John D

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Origin of Life—Out of the Blue John D Angewandte Reviews Chemie International Edition:DOI:10.1002/anie.201506585 Prebiotic SystemsChemistry German Edition:DOI:10.1002/ange.201506585 The Origin of Life—Out of the Blue John D. Sutherland* Keywords: amino acids ·hydrogen cyanide · prebiotic chemistry · ribonucleotides · systems chemistry Angewandte Chemie 104 www.angewandte.org 2016 Wiley-VCH Verlag GmbH &Co. KGaA, Weinheim Angew.Chem. Int. Ed. 2016, 55,104 –121 Angewandte Reviews Chemie Either to sustain autotrophy,orasaprelude to heterotrophy,organic From the Contents synthesis from an environmentally available C1 feedstock molecule is crucial to the origin of life.Recent findings augment key literature 1. Introduction: How to Study the Origin of Life? 105 results and suggest that hydrogen cyanide—“Blausäure”—was that feedstock. 2. The Informational Subsystem 106 3. ADigression 108 “The answer has to come from revisiting the chemistry of HCN” Albert Eschenmoser.[1] 4. The Informational Subsystem—Resumed 108 1. Introduction:How to Study the Origin of Life? 5. First Hints at an Impact Scenario 112 In principle,the origin of life can be studied from geochemistry up,orfrom biology down, but in practice, 6. Chemical Implications of an there are problems with both approaches. Impact Scenario 113 Starting from geochemistry,planetary science suggests that the early Earth could have offered awide range of 7. Refinements to the Impact environments and conditions.Ahuge amount of chemistry is Scenario 114 potentially possible in asubmarine vent, or adrying lagoon, or an impact crater,orareduced atmosphere subject to 8. Chemical Implications of the lightning,orwhatever other scenario one can imagine. Refined Impact Scenario 115 However,there is insufficient constraint from geochemistry per se to settle on one particular scenario,and thence to 9. Linkage of all Subsytems systematically explore its chemistry with aview to uncovering through Cyanosulfidic intrinsically favoured syntheses of biomolecules,ortheir Chemistry 116 precursors,from simple feedstock molecules. Starting from extant biology,phylogeny can only go so far 10. Onwards and Upwards 118 down, and biology before the speciation thresholds that gave rise to the three kingdoms of life cannot be so usefully plumbed in this way.[2] Conceptual and experimental reduc- tion of cells to the simplest (imaginable), minimal cell still subsystem came first and then “invented” the others,with the leaves adauntingly complex system comprising seamlessly primal subsystem being designated according to personal integrated informational, metabolic,catalytic and compart- prejudice (“Darwinian evolution needs informational mole- ment-forming subsystems (Figure 1). But, imagining the cules,soRNA must have come first.”[3] “You cant get by abiotic assembly of such an overall system places huge without building blocks and energy,sometabolism must have demands on hypothetical prebiotic chemistry—surely com- come first.”[4] “Genetics and metabolism without catalysis is pletely different chemistries are needed to make the various hard to imagine,soproteins must have come first.”[5] “The subsystems and surely these different chemistries would development of Darwinian selection is hard to imagine interfere with each other. Therefore,itisnot surprising that without compartments,somembranes must have been there in the past, most in the field assumed that one or other at the outset.”[6]). Several years ago,werealised that this (quadru)polarisa- tion of the field was severely hindering progress,and we planned amore holistic approach. We set out to use experimental chemistry to address two questions,the pre- viously assumed answers to which had led to the polarisation of the field:“Are completely different chemistries needed to make the various subsystems?” “Would these chemistries be compatible with each other?”[7] Our approach was to take the following steps: i) experimentally evaluate the prebiotic chemistry of the various subsystems; [*] Prof. Dr.J.D.Sutherland MRC Laboratory of Molecular Biology Francis Crick Avenue, Cambridge Biomedical Campus Cambridge CB2 0QH (UK) Figure 1. Aminimal cell with emphasis on its subsystems. E-mail:[email protected] Angew.Chem. Int.Ed. 2016, 55,104 –121 2016 Wiley-VCH Verlag GmbH &Co. KGaA, Weinheim 105 Angewandte Reviews Chemie ii)use any commonality of intermediates and/or (by-)prod- ucts to link the subsystems; iii)use the results to infer rough geochemical scenarios; iv) assess other chemical consequences of the inferred scenario. We envisaged that using chemical results to constrain geochemical scenarios,and then letting the inferred scenario back-inform the chemistry would be an iterative process, continued application of which would lead to refinements in both the scenario and the chemistry. 2. The Informational Subsystem We initially set out to explore the assembly chemistry of an informational subsystem based on RNAbecause there is so much to indicate its antiquity in biology.The traditional retrosynthetic disconnection of RNAproceeds thus:RNA ) (activated) nucleotides nucleosides plus phosphate; ) nucleosides ribose plus nucleobases;ribose formalde- ) ) hyde,and nucleobases hydrogen cyanide and other nitro- ) genous precursors.[8] Although this disconnection has not led to acorresponding synthesis under prebiotically plausible Figure 2. Oró’s synthesis of adenine 2 from hydrogen cyanide 1 and conditions,despite many groups efforts over many decades, ammonia (general acid–base catalysis, presumed to operate in most its pursuit has uncovered much fascinating chemistry.Some of steps, is only shown once). The photochemical shortcut discovered by Ferris and Orgel is shown by the red arrow. this chemistry and acouple of the problems encountered are reviewed briefly here because they provide abackdrop for what follows. We start out by touching on nucleobase synthesis.Orós such molecules would be an apparent complexity;straightfor- demonstration that simply mixing hydrogen cyanide 1 and ward pathwaysofstructural self-assembly of these structures ammonia in solution gives rise to adenine 2[9] has been would have to exist, and these pathways would be detectable described as the “rock of faith” of prebiotic chemistry.[10] As experimentally.”[12] In other words,if, through experiment, one modified by Ferris and Orgel,[11] this synthesis produces were to discover efficient synthetic pathways to other natural adenine 2 in reasonable yield from five molecules of hydrogen products along inherently favoured routes,itwould be cyanide 1 (Figure 2). reasonable to conclude that said products originated this To many in the field, the fact that pentamerisation of way,and any complexity would only be in the eye of the something as fundamental as hydrogen cyanide 1 can give rise beholder.Because of his extraordinary success (along with to aheterocycle that is so pervasive in biology is surely no Woodward) in synthesising vitamin B12 by conventional coincidence:“The example of adenine refutes the opinion that means,itwas natural for Eschenmoser to first write about an inquiry into the origin of cofactor structures is futile since it potentially favoured reactions in the prebiotic synthesis of would be apriori impossible to draw conclusions or to study cofactors,[12] but the concept would obviously apply to other the problem experimentally.Were cofactors of prebiotic (or of molecules crucial to biology at the dawn of life.Indeed, the otherwise nonenzymic) origin, then structural complexity of author as aPhD student in Oxford in the mid-1980s,on hearing Eschenmoser talk about this concept in alecture, John Sutherland studied chemistry at the determined to investigate it in relation to RNA. Inherently University of Oxford, and then spent aspell favoured reactions might include those that are catalysed by as aKennedy Scholar at Harvard with another component of the system, those which are part of an Jeremy Knowles. Upon return to the UK, he autocatalytic cycle,those which are catalysed through induced carried out his doctoral work with Jack intramolecularity,[13] or those in which afunctional group in Baldwin at Oxford, and then stayed in amolecule displays out of the ordinary reactivity due to its Oxford first as aJunior Research Fellow and then as aUniversity Lecturer in Organic particular molecular context. Sequential occurence of several Chemistry.In1998 he took achair in such reactions might lead to dramatic syntheses of afew Biological Chemistry at Manchester,and in products (destined to play arole in the advent of biology) 2010 moved to the MRC Laboratory of from mixtures that prophets of gloom would have us believe Molecular Biology in Cambridge as aGroup are prone only to become tar.[14] Leader.Heisinterested in chemistry associ- We continue by reflecting on problems associated with ated with the origin of life. Photo courtesy of sugar synthesis.From the outset, prebiotic chemists relied on MRC Laboratory of Molecular Biology. Butlerows synthesis of formose[15] as asource of sugars.In 106 www.angewandte.org 2016 Wiley-VCH Verlag GmbH &Co. KGaA, Weinheim Angew.Chem. Int. Ed. 2016, 55,104 –121 Angewandte Reviews Chemie intermediates through complexation in such away as to favour the production of ribose ribo-6.The reaction proper starting with formaldehyde 3 (and traces of glycolaldehyde 4) has resisted such attempts,however,[19] although aldopentoses 6 or their derivatives can be preferentially formed by formose reaction variants starting with preformed C2-(and C3-) sugars.[20,21] These preferred routes to pentoses
Load more

Recommended publications
  • A Chemical Engineering Perspective on the Origins of Life
    Processes 2015, 3, 309-338; doi:10.3390/pr3020309 processesOPEN ACCESS ISSN 2227-9717 www.mdpi.com/journal/processes Article A Chemical Engineering Perspective on the Origins of Life Martha A. Grover *, Christine Y. He, Ming-Chien Hsieh and Sheng-Sheng Yu School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Dr. NW, Atlanta, GA 30032, USA; E-Mails: [email protected] (C.Y.H.); [email protected] (M.-C.H.); [email protected] (S.-S.Y.) * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel.: +1-404-894-2878 or +1-404-894-2866. Academic Editor: Michael Henson Received: 29 January 2015 / Accepted: 19 April 2015 / Published: 5 May 2015 Abstract: Atoms and molecules assemble into materials, with the material structure determining the properties and ultimate function. Human-made materials and systems have achieved great complexity, such as the integrated circuit and the modern airplane. However, they still do not rival the adaptivity and robustness of biological systems. Understanding the reaction and assembly of molecules on the early Earth is a scientific grand challenge, and also can elucidate the design principles underlying biological materials and systems. This research requires understanding of chemical reactions, thermodynamics, fluid mechanics, heat and mass transfer, optimization, and control. Thus, the discipline of chemical engineering can play a central role in advancing the field. In this paper, an overview of research in the origins field is given, with particular emphasis on the origin of biopolymers and the role of chemical engineering phenomena. A case study is presented to highlight the importance of the environment and its coupling to the chemistry.
    [Show full text]
  • Prebiotic Chemistry: Geochemical Context and Reaction Screening
    Life 2013, 3, 331-345; doi:10.3390/life3020331 OPEN ACCESS life ISSN 2075-1729 www.mdpi.com/journal/life Article Prebiotic Chemistry: Geochemical Context and Reaction Screening Henderson James Cleaves II Earth Life Science Institute, Tokyo Institute of Technology, Institute for Advanced Study, Princeton, NJ 08540, USA; E-Mail: [email protected] Received: 12 April 2013; in revised form: 17 April 2013 / Accepted: 18 April 2013 / Published: 29 April 2013 Abstract: The origin of life on Earth is widely believed to have required the reactions of organic compounds and their self- and/or environmental organization. What those compounds were remains open to debate, as do the environment in and process or processes by which they became organized. Prebiotic chemistry is the systematic organized study of these phenomena. It is difficult to study poorly defined phenomena, and research has focused on producing compounds and structures familiar to contemporary biochemistry, which may or may not have been crucial for the origin of life. Given our ignorance, it may be instructive to explore the extreme regions of known and future investigations of prebiotic chemistry, where reactions fail, that will relate them to or exclude them from plausible environments where they could occur. Come critical parameters which most deserve investigation are discussed. Keywords: chemical evolution; prebiotic organic reactions-prebiotic reactions in the aqueous phase; prebiotic reactions in the solid state; energy sources on the primitive Earth; mineral catalysis 1. Introduction Prebiotic chemistry is the study of how organic compounds formed and self-organized for the origin of life on Earth and elsewhere [1].
    [Show full text]
  • Formose Reaction Controlled by a Copolymer of N,N-Dimethylacrylamide and 4-Vinylphenylboronic Acid
    polymers Article Formose Reaction Controlled by a Copolymer of N,N-Dimethylacrylamide and 4-Vinylphenylboronic Acid Tomohiro Michitaka, Toru Imai and Akihito Hashidzume * ID Department of Macromolecular Science, Graduate School of Science, Osaka University, Osaka 560-0043, Japan; [email protected] (T.M.); [email protected] (T.I.) * Correspondence: [email protected]; Tel.: +81-6-6850-8174 Received: 8 October 2017; Accepted: 24 October 2017; Published: 25 October 2017 Abstract: The formose reaction is an oligomerization of formaldehyde under basic conditions, which produces a complicated mixture of monosaccharides and sugar alcohols. Selective formation of useful monosaccharides by the formose reaction has been an important challenge. In this study, we have investigated the formose reaction controlled by N,N-dimethylacrylamide/4-vinylphenylboronic acid copolymer (pDMA/VBA) and phenylboronic acid (PBA) because boronic acid compounds form esters with polyols, e.g., monosaccharides and sugar alcohols. We obtained time–conversion data in the presence of these boronic acid compounds, and characterized the products by liquid chromatography-mass spectroscopy and NMR measurements. pDMA/VBA and PBA decelerated the formose reaction because of the formation of boronic acid esters with products. It is noteworthy that the formose reaction in the presence of pDMA/VBA and PBA formed favorably six- and seven-carbon branched monosaccharides and sugar alcohols. Keywords: formose reaction; boronic acid compounds; N,N-dimethylacrylamide/4-vinylphenyl boronic acid copolymer; phenylboronic acid; monosaccharides; sugar alcohols 1. Introduction Carbohydrates are ubiquitous in our life and very important biological materials [1,2]. Carbohydrates can be divided into three categories based on their molecular weight; (1) low molecular weight saccharides, e.g., monosaccharides and disaccharides, (2) oligosaccharides, and (3) polysaccharides.
    [Show full text]
  • Inferring Chemical Reaction Patterns Using Rule Composition in Graph Grammars Jakob L Andersen1,4, Christoph Flamm2*, Daniel Merkle1* and Peter F Stadler2,3,4,5,6,7
    Andersen et al. Journal of Systems Chemistry 2013, 4:4 http://www.jsystchem.com/content/4/1/4 RESEARCH ARTICLE Open Access Inferring chemical reaction patterns using rule composition in graph grammars Jakob L Andersen1,4, Christoph Flamm2*, Daniel Merkle1* and Peter F Stadler2,3,4,5,6,7 Abstract Background: Modeling molecules as undirected graphs and chemical reactions as graph rewriting operations is a natural and convenient approach to modeling chemistry. Graph grammar rules are most naturally employed to model elementary reactions like merging, splitting, and isomerisation of molecules. It is often convenient, in particular in the analysis of larger systems, to summarize several subsequent reactions into a single composite chemical reaction. Results: We introduce a generic approach for composing graph grammar rules to define a chemically useful rule compositions. We iteratively apply these rule compositions to elementary transformations in order to automatically infer complex transformation patterns. As an application we automatically derive the overall reaction pattern of the Formose cycle, namely two carbonyl groups that can react with a bound glycolaldehyde to a second glycolaldehyde. Rule composition also can be used to study polymerization reactions as well as more complicated iterative reaction schemes. Terpenes and the polyketides, for instance, form two naturally occurring classes of compounds of utmost pharmaceutical interest that can be understood as “generalized polymers” consisting of five-carbon (isoprene) and two-carbon units, respectively. Conclusion: The framework of graph transformations provides a valuable set of tools to generate and investigate large networks of chemical networks. Within this formalism, rule composition is a canonical technique to obtain coarse-grained representations that reflect, in a natural way, “effective” reactions that are obtained by lumping together specific combinations of elementary reactions.
    [Show full text]
  • Complex Chemical Reaction Networks from Heuristics-Aided Quantum Chemistry
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Harvard University - DASH Complex Chemical Reaction Networks from Heuristics-Aided Quantum Chemistry The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters. Citation Rappoport, Dmitrij, Cooper J. Galvin, Dmitry Zubarev, and Alán Aspuru-Guzik. 2014. “Complex Chemical Reaction Networks from Heuristics-Aided Quantum Chemistry.” Journal of Chemical Theory and Computation 10 (3) (March 11): 897–907. Published Version doi:10.1021/ct401004r Accessed February 19, 2015 5:14:37 PM EST Citable Link http://nrs.harvard.edu/urn-3:HUL.InstRepos:12697373 Terms of Use This article was downloaded from Harvard University's DASH repository, and is made available under the terms and conditions applicable to Open Access Policy Articles, as set forth at http://nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of- use#OAP (Article begins on next page) Complex Chemical Reaction Networks from Heuristics-Aided Quantum Chemistry Dmitrij Rappoport,∗,† Cooper J Galvin,‡ Dmitry Yu. Zubarev,† and Alán Aspuru-Guzik∗,† Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA, and Pomona College, 333 North College Way, Claremont, CA 91711, USA E-mail: [email protected]; [email protected] Abstract While structures and reactivities of many small molecules can be computed efficiently and accurately using quantum chemical methods, heuristic approaches remain essential for mod- eling complex structures and large-scale chemical systems. Here we present heuristics-aided quantum chemical methodology applicable to complex chemical reaction networks such as those arising in metabolism and prebiotic chemistry.
    [Show full text]
  • The Power of Crowding for the Origins of Life
    Orig Life Evol Biosph (2014) 44:307–311 DOI 10.1007/s11084-014-9382-5 ORIGIN OF LIFE The Power of Crowding for the Origins of Life Helen Greenwood Hansma Received: 2 October 2014 /Accepted: 2 October 2014 / Published online: 14 January 2015 # Springer Science+Business Media Dordrecht 2015 Abstract Molecular crowding increases the likelihood that life as we know it would emerge. In confined spaces, diffusion distances are shorter, and chemical reactions produce fewer and more regular products. Crowding will occur in the spaces between Muscovite mica sheets, which has many advantages as a site for life’s origins. Keywords Muscovite mica . Molecular crowding . Origin of life . Mechanochemistry. Abiogenesis . Chemical confinement effects . Chirality. Protocells Cells are crowded. Protein molecules in cells are typically so close to each other that there is room for only one protein molecule between them (Phillips, Kondev et al. 2008). This is nothing like a dilute ‘prebiotic soup.’ Therefore, by analogy with living cells, the origins of life were probably also crowded. Molecular Confinement Effects Many chemical reactions are limited by the time needed for reactants to diffuse to each other. Shorter distances speed up these reactions. Molecular complementarity is another principle of life in which pairs or groups of molecules form specific interactions (Root-Bernstein 2012). Current examples are: enzymes & substrates & cofactors; nucleic acid base pairs; antigens & antibodies; nucleic acid - protein interactions. Molecular complementarity is likely to have been involved at life’s origins and also benefits from crowding. Mineral surfaces are a likely place for life’s origins and for formation of polymeric molecules (Orgel 1998).
    [Show full text]
  • 4 Carbohydrates
    Basic classes of biomolecules • Aminoacids • Lipids • Carbohydrates (sugars) • Nucleobases • Nucleosides (sugar+nucleobase) Nucleotides - components Phosphates and the prebiotic synthesis of oligonucleotides Activated ribonucleotides in the potentially prebiotic assembly of RNA. Potential P–O bond forming polymerization chemistry is indicated by the curved arrows. Phosphorylation reagents DAP M. A. Pasek, et al. Angew. Chem. Int. Ed. 2008, 47, 7918-7920 A. Eschenmoser, et al. Orig. Life Evol. Biosph. 1999, 29, 333-354 Phosphorylation reagents DAP M. A. Pasek, et al. Angew. Chem. Int. Ed. 2008, 47, 7918-7920 A. Eschenmoser, et al. Orig. Life Evol. Biosph. 1999, 29, 333-354 Phosphorylation of sugars A. Eschenmoser, et al. Angew. Chem. Int. Ed. 2000, 39, 2281-2285 Phosphorylation of sugars A. Eschenmoser, et al. Angew. Chem. Int. Ed. 2000, 39, 2281-2285 Nucleosides - nucleobases + sugars Carbohydrates Formose reaction Alexander Butlerov (1828-1886) St. Petersburg, Kazan, Russia The reaction begins with two formaldehyde molecules condensing to make glycolaldehyde 1 which further reacts in an aldol reaction with another equivalent of formaldehyde to make glyceraldehyde 2. An aldose-ketose isomerization of 2 forms dihydroxyacetone 3 which can Ronald Breslow (1931-) react with 1 to form ribulose 4, and through another isomerization ribose 5. Molecule 3 also Columbia University, USA can react with formaldehyde to produce tetrulose 6 and then aldoltetrose 7. Molecule 7 can split into 2 in a retro-aldol reaction. Formaldehyde condensation Aldol
    [Show full text]
  • Gravitational Influence on Human Living Systems and the Evolution Of
    molecules Review Gravitational Influence on Human Living Systems and the Evolution of Species on Earth Konstantinos Adamopoulos 1 , Dimitrios Koutsouris 1 , Apostolos Zaravinos 2,* and George I. Lambrou 1,3,* 1 School of Electrical and Computer Engineering, Biomedical Engineering Laboratory, National Technical University of Athens, Heroon Polytechneiou 9, Zografou, 15780 Athens, Greece; [email protected] (K.A.); [email protected] (D.K.) 2 Department of Life Sciences, School of Sciences, European University Cyprus, 1516 Nicosia, Cyprus 3 First Department of Pediatrics, Choremeio Research Laboratory, National and Kapodistrian University of Athens, Thivon & Levadeias 8, Goudi, 11527 Athens, Greece * Correspondence: [email protected] (A.Z.); [email protected] (G.I.L.); Tel.: +357-22713043 (A.Z.); +30-210-7467427 (G.I.L.) Abstract: Gravity constituted the only constant environmental parameter, during the evolutionary period of living matter on Earth. However, whether gravity has affected the evolution of species, and its impact is still ongoing. The topic has not been investigated in depth, as this would require frequent and long-term experimentations in space or an environment of altered gravity. In addition, each organism should be studied throughout numerous generations to determine the profound biological changes in evolution. Here, we review the significant abnormalities presented in the cardiovascular, immune, vestibular and musculoskeletal systems, due to altered gravity conditions. We also review the impact that gravity played in the anatomy of snakes and amphibians, during their evolution. Overall, it appears that gravity does not only curve the space–time continuum but the biological Citation: Adamopoulos, K.; continuum, as well. Koutsouris, D.; Zaravinos, A.; Lambrou, G.I.
    [Show full text]
  • Fermentation of Dihydroxyacetone by Engineered Escherichia Coli and Klebsiella Variicola to Products
    Fermentation of dihydroxyacetone by engineered Escherichia coli and Klebsiella variicola to products Liang Wanga, Diane Chauliaca,1, Mun Su Rheea,2, Anushadevi Panneerselvama, Lonnie O. Ingrama,3, and K. T. Shanmugama,3 aDepartment of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611 Contributed by Lonnie O. Ingram, March 21, 2018 (sent for review January 18, 2018; reviewed by John W. Frost and F. Robert Tabita) Methane can be converted to triose dihydroxyacetone (DHA) by process, formaldehyde can also be produced biologically from chemical processes with formaldehyde as an intermediate. Carbon CO2 with formate as an intermediate (Fig. 1) (7). Dickens and dioxide, a by-product of various industries including ethanol/ Williamson reported as early as 1958 that DHA can be produced butanol biorefineries, can also be converted to formaldehyde biologically by transketolation of hydroxypyruvate and formalde- and then to DHA. DHA, upon entry into a cell and phosphorylation hyde (8). This transketolase is implicated in a unique pentose– to DHA-3-phosphate, enters the glycolytic pathway and can be phosphate–dependent pathway (DHA cycle) in methanol-utilizing fermented to any one of several products. However, DHA is yeast that fixes formaldehyde to xylulose-5-phosphate, yielding inhibitory to microbes due to its chemical interaction with cellular DHA as an intermediate in the production of glyceraldehyde-3- components. Fermentation of DHA to D-lactate by Escherichia coli phosphate in a cyclic mode (9). DHA in the cytoplasm is phos- strain TG113 was inefficient, and growth was inhibited by 30 g·L−1 phorylated by DHA kinase and/or glycerol kinase, and the DHA-P DHA.
    [Show full text]
  • Ii COMBINED FEED MOLARITY of Ca (OH)
    Worcester Polytechnic Institute Department of Chemical Engineering Worcester, Massachusetts 01609 Final Report for NASA Grant No. NGR 22-017-023 "An Interfaced System for Production of Methane in a Spacecraft June 30, 1973 , -7-27588 92 3 SYSTEM (NASA-CR-138 ) AN INTERFACED ;FOR PRODUCTICN OF METHANE IN A SPACECRAFT Final Report (Worcester Unclas Polytechnic Inst.) 37 p HC $5.00 CSCL 07C G3/06 1621 - - -~CSCL 07C G3/06 162 Homogeneously Catalyzed Formaldehyde Condensation to Carb Concentration Instabilities, Nature of the Catalyst, and Mechanisms by Alvin H. Weiss and Tom John Chemical Engineering Department Worcester Polytechnic Institute Worcester, Massachusetts 01609 ABSTRACT The formose reaction, the homogeneously catalyzed conden- sation of formaldehyde to sugars, proceeds simultaneously with Cannizzaro and crossed-Cannizzaro reactions. Reaction studies in a continuous stirred tank reactor have shown that rate instabili- ties are exhibited. There are temperature instabilities as well as concentration instabilities in calcium hydroxide catalyst, formaldehyde reactant, and hydroxyl ion. It is postulated that Ca(OH)+ is the actual catalytic species for the formose system. A unifying mechanism is developed that uses observed rate phenomena to explain why almost any base, regardless of valence, is a catalyst for the formose and Cannizzaro reactions of formaldehyde. The mechanism postulates that reactions proceed from a common intermediate complexed species, and the selectivity for each reaction depends on the nature of the catalyst forming the carbohydrate complex. The catalytic mechanism explains the Lobry de Bruyn-van Eckenstein aldose-ketose rearrangements and mutarotations of sugars that also proceed in the system. Running Title: Formose Instabilities -1- Introduction The calcium hydroxide catalyzed condensation of formaldehyde to carbohydrates .
    [Show full text]
  • Impact-Induced Amino Acid Formation on Hadean Earth and Noachian Mars
    www.nature.com/scientificreports OPEN Impact-induced amino acid formation on Hadean Earth and Noachian Mars Yuto Takeuchi1, Yoshihiro Furukawa1 ✉ , Takamichi Kobayashi2, Toshimori Sekine3,4, Naoki Terada5 & Takeshi Kakegawa1 Abiotic synthesis of biomolecules is an essential step for the chemical origin of life. Many attempts have succeeded in synthesizing biomolecules, including amino acids and nucleobases (e.g., via spark discharge, impact shock, and hydrothermal heating), from reduced compounds that may have been limited in their availabilities on Hadean Earth and Noachian Mars. On the other hand, formation of amino-acids and nucleobases from CO2 and N2 (i.e., the most abundant C and N sources on Earth during the Hadean) has been limited via spark discharge. Here, we demonstrate the synthesis of amino acids by laboratory impact-induced reactions among simple inorganic mixtures: Fe, Ni, Mg2SiO4, H2O, CO2, and N2, by coupling the reduction of CO2, N2, and H2O with the oxidation of metallic Fe and Ni. These chemical processes simulated the possible reactions at impacts of Fe-bearing meteorites/asteroids on oceans with a CO2 and N2 atmosphere. The results indicate that hypervelocity impact was a source of amino acids on the Earth during the Hadean and potentially on Mars during the Noachian. Amino acids formed during such events could more readily polymerize in the next step of the chemical evolution, as impact events locally form amino acids at the impact sites. Te composition of early Earth’s atmosphere has been a subject of discussion. Te atmosphere was once regarded 1 as strongly reduced, composed mostly of CH4, NH3, and H2 .
    [Show full text]
  • The Chemical Origin of Behavior Is Rooted in Abiogenesis
    Life 2012, 2, 313-322; doi:10.3390/life2040313 OPEN ACCESS life ISSN 2075-1729 www.mdpi.com/journal/life Article The Chemical Origin of Behavior is Rooted in Abiogenesis Brian C. Larson, R. Paul Jensen and Niles Lehman * Department of Chemistry, Portland State University, P.O. Box 751, Portland, OR 97207, USA; E-Mails: [email protected] (B.C.L.); [email protected] (R.P.J.) * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel.: +1-503-725-8769. Received: 6 August 2012; in revised form: 29 September 2012 / Accepted: 2 November 2012 / Published: 7 November 2012 Abstract: We describe the initial realization of behavior in the biosphere, which we term behavioral chemistry. If molecules are complex enough to attain a stochastic element to their structural conformation in such as a way as to radically affect their function in a biological (evolvable) setting, then they have the capacity to behave. This circumstance is described here as behavioral chemistry, unique in its definition from the colloquial chemical behavior. This transition between chemical behavior and behavioral chemistry need be explicit when discussing the root cause of behavior, which itself lies squarely at the origins of life and is the foundation of choice. RNA polymers of sufficient length meet the criteria for behavioral chemistry and therefore are capable of making a choice. Keywords: behavior; chemistry; free will; RNA; origins of life 1. Introduction Behavior is an integral feature of life. Behavior is manifest when a choice is possible, and a living entity responds to its environment in one of multiple possible ways.
    [Show full text]