Welcome to the php ebenezer's messageboard
see bottom for more info

HOME


Re: Re: Re: Re: Re: Re: Re: Re: Feynman and I (20/06/18 17:26:03)
    This strict Christianity is a part of Europe's religious past. I am sure that all those extreme abuses were preparing the thinking people for a rebellion against, and, eventually, the expulsion of religion from politics.

    I do not want it back in any form. The recent events in West Asia is a reminder that we are not rid of the concept or the reality of the God state. I think we should be more active in removing the basis for it - by education about what is possible and what is impossible.

    --

    So - I say that life created itself, and there are theories about the mechanisms operating - within the laws of nature. It is much harder so give a plausible mechanism for the existence of an almighty invisible all-knowing ubiquitous god having created himself and thereafter the universe and all life by intelligent design. Actually - I have not seem one single proposal of a physical mechanism - it is all about faith - and ignorance.

    " Since their discovery, hydrothermal vents have been relevant to concepts that surround the origin of life. At the simplest level, there are two kinds of hydrothermal vents: the hot (approximately 350°C) black smoker type, the chemistry of which is driven by the magma-chamber that resides below ocean-floor spreading zones, and the cooler (approximately 50–90°C) Lost City type, the chemistry of which is driven not by magma, but by a process called serpentinization.

    Serpentinization is a H2-producing geochemical reaction that has been operation in hydrothermal systems for as long as there has been water on the Earth. Its reducing power is sufficient to generate substantial amounts of abiogenic CH4 and short hydrocarbons in the effluent of some modern hydrothermal vents.

    In the study of the origin of life, major unresolved issues concern the source of sustained chemical energy and the source of reduced carbon compounds. The CO2-reducing geochemistry of modern hydrothermal vents provides a model for our understanding of how such processes might have been possible at the dawn of biochemistry.

    Methanogens and acetogens satisfy their carbon needs through the acetyl-coenzyme A pathway, an energy-releasing pathway of CO2 fixation, if given sufficient environmental H2 and CO2. The authors consider the idea that the CH4-producing and acetate-producing geochemistry of hydrothermal vents is the abiogenic precursor of modern microbial CH4 and acetate production.

    This suggests that the evolutionary starting point of microbial metabolism might have been an energy-releasing geochemical process in which CO2 served as the acceptor for electrons that stemmed from H2 generated by serpentinization. The naturally chemiosmotic nature of alkaline hydrothermal systems, such as Lost City, might be important to the origin of life issue, but in a somewhat unexpected way that, in turn, helps to explain why chemiosmotic coupling through ATPases is universal throughout the microbial world."

    https://www.nature.com/articles/nrmicro1991

    ---

    " A new theory proposes the primordial life-forms that gave rise to all life on Earth left deep-sea vents because of their "invention" of a tiny pump. These primitive cellular pumps would have powered life-giving chemical reactions.

    The idea, detailed Dec. 20 in the journal Cell, could help explain two mysteries of life's early origin: How did the earliest proto-cells power chemical reactions to make the organic building blocks of life; and how did they leave hydrothermal vents to colonize early Earth's oceans?

    Authors of the new theory argue the environmental conditions in porous hydrothermal vents — where heated, mineral-laden seawater spews from cracks in the ocean crust — created a gradient in positively charged protons that served as a "battery" to fuel the creation of organic molecules and proto-cells.

    Later, primitive cellular pumps gradually evolved the ability to use a different type of gradient — the difference in sodium particles inside and outside the cell — as a battery to power the construction of complex molecules like proteins. And, voilà, the proto-cells could leave the deep-sea hydrothermal vents. [Image Gallery: Unique Life at Deep-Sea Vents]

    "A coupling of proton gradients and sodium gradients may have played a major role in the origin of life. This is really cool, novel stuff," Jan Amend, a researcher at the University of Southern California, who was not involved in the study, wrote in an email to LiveScience. The study reflects the increasingly popular idea that a simple, everyday source of power, not a rare occurrence like a lightning strike, could have provided the power to initially create life, he said.

    Deep-sea start

    Many scientists think life got its start around 3.7 billion years ago in deep-sea hydrothermal vents. But figuring out just how complex, carbon-based life formed in that primordial stew has been tricky.

    Somehow, the precursors of life harnessed carbon dioxide and hydrogen available in those primitive conditions to create the building blocks of life, such as amino acids and nucleotides (building blocks of DNA). But those chemical reactions require a power source, said study co-author Nick Lane, a researcher at the University College London.

    Now, Lane and William Martin, of the Institute of Molecular Evolution at the Heinrich Heine University in Germany, propose that the rocky mineral walls in ocean-floor vents could have provided the means.

    The theory goes: At the time of life's origin, the early ocean was acidic and filled with positively charged protons, while the deep-sea vents spewed out bitter alkaline fluid, which is rich in negatively charged hydroxide ions, Lane told LiveScience.

    The vents created furrowed rocky, iron- and sulfur-rich walls full of tiny pores that separated the warm alkaline vent fluid from the cooler, acidic seawater. The interface between the two created a natural charge gradient.

    "It's a little bit like a battery," Lane told LiveScience.

    That battery then powered the chemical transformation of carbon dioxide and hydrogen into simple carbon-based molecules such as amino acids or proteins. Eventually that gradient drove the creation of cellular membranes, complicated proteins and ribonucleic acid (RNA), a molecule similar to DNA.

    Leaving the vents

    At that point, primitive cells used the thin, serpentine walls of the vent to corral the new carbon-based molecules together into precursors of cells and used the charge gradient in the environment to power the building of more complex organic chemicals.

    But in order to leave the vent, primitive cells would have needed some way to carry a power-producing gradient with them — think battery pack. To solve that problem, the team looked at existing archaea bacteria in deep-sea vents.

    Those primeval life-forms use a simple type of cellular pump that pushes sodium out of the cell while pulling positively charged protons in. The team proposed that a precursor to that cellular pump evolved in the membranes of the proto-cells.

    The membrane started out very leaky, but over time, the membranes would have slowly closed, preventing much larger sodium particles from leaving the cell while smaller protons could still slip through. That enabled the proto-cells to still use the existing power-source in the environment — the charge gradient — while gradually evolving an independent way of getting power.

    Eventually, when the pores closed completely, the primitive cells would have had a sodium pump that could power their cellular reactions, enabling more complex life to form. They could then leave their birthplace.

    Testing the idea, however, will be tricky, Amend told LiveScience. "Mimicking natural conditions in the lab is a lot more difficult than it sounds.""

    ( A new theory proposes the primordial life-forms that gave rise to all life on Earth left deep-sea vents because of their "invention" of a tiny pump. These primitive cellular pumps would have powered life-giving chemical reactions.

    The idea, detailed Dec. 20 in the journal Cell, could help explain two mysteries of life's early origin: How did the earliest proto-cells power chemical reactions to make the organic building blocks of life; and how did they leave hydrothermal vents to colonize early Earth's oceans?

    Authors of the new theory argue the environmental conditions in porous hydrothermal vents — where heated, mineral-laden seawater spews from cracks in the ocean crust — created a gradient in positively charged protons that served as a "battery" to fuel the creation of organic molecules and proto-cells.

    Later, primitive cellular pumps gradually evolved the ability to use a different type of gradient — the difference in sodium particles inside and outside the cell — as a battery to power the construction of complex molecules like proteins. And, voilà, the proto-cells could leave the deep-sea hydrothermal vents. [Image Gallery: Unique Life at Deep-Sea Vents]

    "A coupling of proton gradients and sodium gradients may have played a major role in the origin of life. This is really cool, novel stuff," Jan Amend, a researcher at the University of Southern California, who was not involved in the study, wrote in an email to LiveScience. The study reflects the increasingly popular idea that a simple, everyday source of power, not a rare occurrence like a lightning strike, could have provided the power to initially create life, he said.

    Deep-sea start

    Many scientists think life got its start around 3.7 billion years ago in deep-sea hydrothermal vents. But figuring out just how complex, carbon-based life formed in that primordial stew has been tricky.

    Somehow, the precursors of life harnessed carbon dioxide and hydrogen available in those primitive conditions to create the building blocks of life, such as amino acids and nucleotides (building blocks of DNA). But those chemical reactions require a power source, said study co-author Nick Lane, a researcher at the University College London.

    Now, Lane and William Martin, of the Institute of Molecular Evolution at the Heinrich Heine University in Germany, propose that the rocky mineral walls in ocean-floor vents could have provided the means.

    The theory goes: At the time of life's origin, the early ocean was acidic and filled with positively charged protons, while the deep-sea vents spewed out bitter alkaline fluid, which is rich in negatively charged hydroxide ions, Lane told LiveScience.

    The vents created furrowed rocky, iron- and sulfur-rich walls full of tiny pores that separated the warm alkaline vent fluid from the cooler, acidic seawater. The interface between the two created a natural charge gradient.

    "It's a little bit like a battery," Lane told LiveScience.

    That battery then powered the chemical transformation of carbon dioxide and hydrogen into simple carbon-based molecules such as amino acids or proteins. Eventually that gradient drove the creation of cellular membranes, complicated proteins and ribonucleic acid (RNA), a molecule similar to DNA.

    Leaving the vents

    At that point, primitive cells used the thin, serpentine walls of the vent to corral the new carbon-based molecules together into precursors of cells and used the charge gradient in the environment to power the building of more complex organic chemicals.

    But in order to leave the vent, primitive cells would have needed some way to carry a power-producing gradient with them — think battery pack. To solve that problem, the team looked at existing archaea bacteria in deep-sea vents.

    Those primeval life-forms use a simple type of cellular pump that pushes sodium out of the cell while pulling positively charged protons in. The team proposed that a precursor to that cellular pump evolved in the membranes of the proto-cells.

    The membrane started out very leaky, but over time, the membranes would have slowly closed, preventing much larger sodium particles from leaving the cell while smaller protons could still slip through. That enabled the proto-cells to still use the existing power-source in the environment — the charge gradient — while gradually evolving an independent way of getting power.

    Eventually, when the pores closed completely, the primitive cells would have had a sodium pump that could power their cellular reactions, enabling more complex life to form. They could then leave their birthplace.

    Testing the idea, however, will be tricky, Amend told LiveScience. "Mimicking natural conditions in the lab is a lot more difficult than it sounds.")

    ---
    "While proponents of the primordial soup theory argue that electrostatic discharges or the Sun’s ultraviolet radiation drove life’s first chemical reactions, modern life is not powered by any of these volatile energy sources. Instead, at the core of life’s energy production are ion gradients across biological membranes. Nothing even remotely similar could have emerged within the warm ponds of primeval broth on Earth’s surface. In these environments, chemical compounds and charged particles tend to get evenly diluted instead of forming gradients or non-equilibrium states that are so central to life.

    Deep-sea hydrothermal vents represent the only known environment that could have created complex organic molecules with the same kind of energy-harnessing machinery as modern cells. Seeking the origins of life in the primordial soup made sense when little was known about the universal principles of life’s energetics. But as our knowledge expands, it is time to embrace alternative hypotheses that recognize the importance of the energy flux driving the first biochemical reactions. These theories seamlessly bridge the gap between the energetics of living cells and non-living molecules."

    (https://qz.com/761430/weve-been-wrong-about-the-origins-of-life-for-90-years/)
e


back to main board expand thread
Name email
Subject
Enter your message here :
Ask for confirmation if modified Are you not a spammer?
   
Show allowed tags
 
Show me the last post since :
local time shift :

come again

messageboard's PHP script is a courtesy of Laurent

 This board has been visited 243684 timesCurrent time is 19/09/18 09:49:20
Re: Re: Re: Re: Re: Re: Re: Re: Feynman and I