scholarly journals Did Cyclic Metaphosphates Have a Role in the Origin of Life?

2021 ◽  
Author(s):  
Thomas Glonek
Keyword(s):  
Organic Molecules ◽  
Water Soluble ◽  
Holliday Junction ◽  
Additional Energy ◽  
Condensed Phosphate ◽  
Geological Processes ◽  
The Origin Of Life ◽  
Complex Forms ◽  
Self Replication

AbstractHow life began still eludes science life, the initial progenote in the context presented herein, being a chemical aggregate of primordial inorganic and organic molecules capable of self-replication and evolution into ever increasingly complex forms and functions.Presented is a hypothesis that a mineral scaffold generated by geological processes and containing polymerized phosphate units was present in primordial seas that provided the initiating factor responsible for the sequestration and organization of primordial life’s constituents. Unlike previous hypotheses proposing phosphates as the essential initiating factor, the key phosphate described here is not a polynucleotide or just any condensed phosphate but a large (in the range of at least 1 kilo-phosphate subunits), water soluble, cyclic metaphosphate, which is a closed loop chain of polymerized inorganic phosphate residues containing only phosphate middle groups. The chain forms an intrinsic 4-phosphate helix analogous to its structure in Na Kurrol’s salt, and as with DNA, very large metaphosphates may fold into hairpin structures. Using a Holliday-junction-like scrambling mechanism, also analogous to DNA, rings may be manipulated (increased, decreased, exchanged) easily with little to no need for additional energy, the reaction being essentially an isomerization.A literature review is presented describing findings that support the above hypothesis. Reviewed is condensed phosphate inorganic chemistry including its geological origins, biological occurrence, enzymes and their genetics through eukaryotes, polyphosphate functions, circular polynucleotides and the role of the Holliday junction, previous biogenesis hypotheses, and an Eoarchean Era timeline.

Aldehyde Carboxylation: A Concise DFT Mechanistic Study and a Hypothetical Role of CO2 in the Origin of Life

Synlett ◽  
2019 ◽  
Vol 30 (09) ◽  
pp. 987-996 ◽  
Author(s):  
Martin Juhl ◽  
Myungjo Kim ◽  
Hee-Yoon Lee ◽  
Mu-Hyun Baik ◽  
Ji-Woong Lee
Keyword(s):  
Reductive Amination ◽  
Potential Role ◽  
Organic Molecules ◽  
Carbon Fixation ◽  
Mechanistic Study ◽  
Keto Acids ◽  
The Origin Of Life ◽  
Low Efficiency ◽  
Primordial Soup

Carbon dioxide is arguably one of the most stable carbon-based molecules, yet enzymatic carbon fixation processes enabled the sustainable life cycle on Earth. Chemical reactions involving CO2-functionalization often suffer from low efficiency with highly reactive substrates. We recently reported mild carboxylation of aldehydes to furnish α-keto acids – a building block for chiral α-amino acids via reductive amination. Here, we discuss potential reaction mechanisms of aldehyde carboxylation reactions based on two promoters: NHCs and KCN in the carboxylation reaction. New DFT mechanistic studies suggested a lower reaction barrier for a CO2-functionalization step, implying a potential role of CO2 in prebiotic evolution of organic molecules in the primordial soup.1 Introduction: Aldehydes, Benzoins, Carboxylic Acids2 CO2-Activation: NHC, Cyanide, Lewis Acid and Water3 A Breslow Intermediate: Benzoin Reaction vs. Carboxylation with CO2 4 Carboxylation in the Primordial Soup5 Conclusion

scholarly journals THE ECOLOGICAL ROLE OF CLAYS AND CLAY MINERALS

2019 ◽  
Vol 14 (1) ◽  
pp. 60-71
Author(s):  
V. А. KOROLEV
Keyword(s):  
Origin Of Life ◽  
Clay Minerals ◽  
Great Influence ◽  
Ecological Function ◽  
Ecological Role ◽  
Hydrothermal Conditions ◽  
Ecological Functions ◽  
Geological Processes ◽  
The Origin Of Life

The article considers the ecological role played by clays and clay minerals in the ecosystem and the biosphere as a whole. The value of clays and clay minerals in the origin of life on Earth and the formation of RNA are analyzed, due to the periodicity of the microstructure of these minerals, their physicochemical activity and sorption capacity with respect to amino acids, nucleotides, proteins and RNA. The processes of interaction of clay minerals with organic matter are considered, including under conditions of hydrothermal conditions, which have specific features that contribute to the origin of life. In addition, the ecological functions of the lithosphere due to clays and clay minerals were analyzed. It is shown that clays and clay minerals perform the most important ecological resource function, being a valuable mineral resource and mineral, participating in providing biota (including humans) with various mineral and energy resources of minerals, in providing biophilic resources, in providing renewable resources (water, oil and gas), in providing resources of the geological space, etc. Also, the clays perform an important ecological geochemical function, which consists in their participation in the geochemistry processes of the lithosphere and the formation of specific geochemical barriers that perform protective ecological functions on the migration routes of various contaminants. The ecological geodynamic function of clays consists in their influence on the development of endogenous and exogenous geological processes affecting the state and functioning of ecosystems. Finally, the participation of clays in ensuring the geophysical ecological function of the lithosphere consists in their influence on the formation of both natural and man-made geophysical fields in ecological-geological systems. Thus, clays and clay minerals have a great influence on ecological and geological systems, they are involved in the formation of all the most important ecological functions of the lithosphere: resource, geochemical, geodynamic and geophysical. Among them, the most significant is the role of clays and clay minerals in ensuring the resource ecological function of the lithosphere.

Making gender visible in family business: past and present

2012 ◽  
Vol 13 (1) ◽  
Author(s):  
Paloma Fernández Pérez ◽  
Eleanor Hamilton
Keyword(s):  
Family Business ◽  
Family Firms ◽  
Business Leadership ◽  
Legal Rules ◽  
Developed Economies ◽  
The Family ◽  
Interdisciplinary Synthesis ◽  
Complex Forms ◽  
Rules Of The Game

This  study  contributes  to  developing  our understanding of gender and family business. It draws on studies from the business history and management literatures and provides an interdisciplinary synthesis. It illuminates the role of women and their participation in the entrepreneurial practices of the family and the business. Leadership is introduced as a concept to examine the roles of women and men in family firms, arguing that concepts used  by  historians or economists like ownership and management have served to make women ‘invisible’, at least in western developed economies in which owners and managers have been historically due to legal rules  of  the  game  men,  and  minoritarily women. Finally, it explores gender relations and  the  notion  that  leadership  in  family business  may  take  complex  forms  crafte within constantly changing relationships.

scholarly journals Persistent Atrial Fibrillation: The Role of Left Atrial Posterior Wall Isolation and Ablation Strategies

2021 ◽  
Vol 10 (14) ◽  
pp. 3129
Author(s):  
Riyaz A. Kaba ◽  
Aziz Momin ◽  
John Camm
Keyword(s):  
Atrial Fibrillation ◽  
Left Atrial ◽  
Pulmonary Veins ◽  
Treatment Strategies ◽  
Persistent Atrial Fibrillation ◽  
Posterior Wall ◽  
Cardiovascular Death ◽  
Good Effect ◽  
Complex Forms

Atrial fibrillation (AF) is a global disease with rapidly rising incidence and prevalence. It is associated with a higher risk of stroke, dementia, cognitive decline, sudden and cardiovascular death, heart failure and impairment in quality of life. The disease is a major burden on the healthcare system. Paroxysmal AF is typically managed with medications or endocardial catheter ablation to good effect. However, a large proportion of patients with AF have persistent or long-standing persistent AF, which are more complex forms of the condition and thus more difficult to treat. This is in part due to the progressive electro-anatomical changes that occur with AF persistence and the spread of arrhythmogenic triggers and substrates outside of the pulmonary veins. The posterior wall of the left atrium is a common site for these changes and has become a target of ablation strategies to treat these more resistant forms of AF. In this review, we discuss the role of the posterior left atrial wall in persistent and long-standing persistent AF, the limitations of current endocardial-focused treatment strategies, and future perspectives on hybrid epicardial–endocardial approaches to posterior wall isolation or ablation.

scholarly journals Formation of Thiophene under Simulated Volcanic Hydrothermal Conditions on Earth—Implications for Early Life on Extraterrestrial Planets?

Life ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 149
Author(s):  
Thomas Geisberger ◽  
Jessica Sobotta ◽  
Wolfgang Eisenreich ◽  
Claudia Huber
Keyword(s):  
Fatty Acids ◽  
Hydrogen Sulfide ◽  
Early Life ◽  
Organic Molecules ◽  
Metal Sulfides ◽  
Early Earth ◽  
Hydrothermal Conditions ◽  
Evolution Of Metabolism ◽  
Thiophene Derivatives ◽  
The Origin Of Life

Thiophene was detected on Mars during the Curiosity mission in 2018. The compound was even suggested as a biomarker due to its possible origin from diagenesis or pyrolysis of biological material. In the laboratory, thiophene can be synthesized at 400 °C by reacting acetylene and hydrogen sulfide on alumina. We here show that thiophene and thiophene derivatives are also formed abiotically from acetylene and transition metal sulfides such as NiS, CoS and FeS under simulated volcanic, hydrothermal conditions on Early Earth. Exactly the same conditions were reported earlier to have yielded a plethora of organic molecules including fatty acids and other components of extant metabolism. It is therefore tempting to suggest that thiophenes from abiotic formation could indicate sites and conditions well-suited for the evolution of metabolism and potentially for the origin-of-life on extraterrestrial planets.

scholarly journals Emerging multifaceted roles of BAP1 complexes in biological processes

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Aileen Patricia Szczepanski ◽  
Lu Wang
Keyword(s):  
Transcriptional Repression ◽  
Target Genes ◽  
Regulatory Mechanisms ◽  
Biological Processes ◽  
Multiprotein Complex ◽  
Downstream Target ◽  
Evolutionarily Conserved ◽  
Complex Forms ◽  
Polycomb Repressive Complex 1

AbstractHistone H2AK119 mono-ubiquitination (H2AK119Ub) is a relatively abundant histone modification, mainly catalyzed by the Polycomb Repressive Complex 1 (PRC1) to regulate Polycomb-mediated transcriptional repression of downstream target genes. Consequently, H2AK119Ub can also be dynamically reversed by the BAP1 complex, an evolutionarily conserved multiprotein complex that functions as a general transcriptional activator. In previous studies, it has been reported that the BAP1 complex consists of important biological roles in development, metabolism, and cancer. However, identifying the BAP1 complex’s regulatory mechanisms remains to be elucidated due to its various complex forms and its ability to target non-histone substrates. In this review, we will summarize recent findings that have contributed to the diverse functional role of the BAP1 complex and further discuss the potential in targeting BAP1 for therapeutic use.

scholarly journals Changes in CO2 Adsorption Affinity Related to Ni Doping in FeS Surfaces: A DFT-D3 Study

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 486
Author(s):  
Aleksandar Zivković ◽  
Michiel Somers ◽  
Eloi Camprubi ◽  
Helen E. King ◽  
Mariette Wolthers ◽  
...  
Keyword(s):  
Density Functional ◽  
Organic Molecules ◽  
Ni Doping ◽  
Functional Theory ◽  
Small Organic Molecules ◽  
Adsorption Affinity ◽  
The Origin Of Life ◽  
Carbon Dioxide Co2 ◽  
Partial Desorption ◽  
Good Agreement

Metal sulphides constitute cheap, naturally abundant, and environmentally friendly materials for energy storage applications and chemistry. In particular, iron (II) monosulphide (FeS, mackinawite) is a material of relevance in theories of the origin of life and for heterogenous catalytic applications in the conversion of carbon dioxide (CO2) towards small organic molecules. In natural mackinawite, Fe is often substituted by other metals, however, little is known about how such substitutions alter the chemical activity of the material. Herein, the effect of Ni doping on the structural, electronic, and catalytic properties of FeS surfaces is explored via dispersion-corrected density functional theory simulations. Substitutional Ni dopants, introduced on the Fe site, are readily incorporated into the pristine matrix of FeS, in good agreement with experimental measurements. The CO2 molecule was found to undergo deactivation and partial desorption from the doped surfaces, mainly at the Ni site when compared to undoped FeS surfaces. This behaviour is attributed to the energetically lowered d-band centre position of the doped surface, as a consequence of the increased number of paired electrons originating from the Ni dopant. The reaction and activation energies of CO2 dissociation atop the doped surfaces were found to be increased when compared to pristine surfaces, thus helping to further elucidate the role Ni could have played in the reactivity of FeS. It is expected that Ni doping in other Fe-sulphides may have a similar effect, limiting the catalytic activity of these phases when this dopant is present at their surfaces.

The biological activity of glucagon–phospholipid complexes

1983 ◽  
Vol 61 (7) ◽  
pp. 688-691 ◽  
Author(s):  
J. J. Liepnieks ◽  
P. Stoskopf ◽  
E. A. Carrey ◽  
C. Prosser ◽  
R. M. Epand
Keyword(s):  
Biological Activity ◽  
Adenylate Cyclase ◽  
Plasma Membranes ◽  
Bovine Brain ◽  
Water Soluble ◽  
Dipalmitoyl Phosphatidylcholine ◽  
Dimyristoyl Phosphatidylcholine ◽  
Lipoprotein Complex ◽  
Stimulation Of

Glucagon can form water-soluble complexes with phospholipids. The incorporation of glucagon into these lipoprotein particles reduces the biological activity of the hormone. The effect is observed only at temperatures below the phase transition temperature of the phospholipid and results in a decreased stimulation of the adenylate cyclase of rat liver plasma membranes by the lipoprotein complex as compared with the hormone in free solution. Two- to five-fold higher concentrations of glucagon are required for half-maximal stimulation of adenylate cyclase when the hormone is complexed with dimyristoyl phosphatidylcholine, dipalmitoyl phosphatidylcholine, or bovine brain sphingomyelin. A possible role of lipoprotein-associated hormones in the development of insulin resistance is discussed.

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