MSGID: 1:317/3 649d08e5   
   PID: hpt/lnx 1.9.0-cur 2019-01-08   
   TID: hpt/lnx 1.9.0-cur 2019-01-08   
    How urea may have been the gateway to life    
      
     Date:   
         June 28, 2023   
     Source:   
         ETH Zurich   
     Summary:   
         Urea reacts extremely quickly under the conditions that existed   
         when our planet was newly formed. This new insight furthers our   
         understanding of how life on Earth might have begun.   
      
      
         Facebook Twitter Pinterest LinkedIN Email   
      
   ==========================================================================   
   FULL STORY   
   ==========================================================================   
   Researchers from ETH Zurich and the University of Geneva have developed a   
   new method that allows them to observe chemical reactions taking place in   
   liquids at extremely high temporal resolution. This means they can examine   
   how molecules change within just a few femtoseconds -- in other words,   
   within a few quadrillionths of a second. The method is based on earlier   
   work done by the same group of researchers led by Hans Jakob Wo"rner,   
   Professor of Physical Chemistry at ETH Zurich. That work yielded similar   
   results for reactions that take place in gas environments.   
      
   To expand their X-ray spectroscopy observations to liquids, the   
   researchers had to design an apparatus capable of producing a liquid   
   jet with a diameter of less than one micrometre in a vacuum. This was   
   essential because if the jet were any wider, it would absorb some of   
   the X-rays used to measure it.   
      
   Molecular pioneer in biochemistry Using the new method, the researchers   
   were able to gain insights into the processes that led to the emergence   
   of life on Earth. Many scientists assume that urea played a pivotal   
   role here. It is one of the simplest molecules containing both carbon   
   and nitrogen. What's more, it's highly likely that urea was present   
   even when the Earth was very young, something that was also suggested   
   by a famous experiment done in the 1950s: American scientist Stanley   
   Miller concocted a mixture of those gases believed to have made up the   
   planet's primordial atmosphere and exposed it to the conditions of a   
   thunderstorm. This produced a series of molecules, one of which was urea.   
      
   According to current theories, the urea could have become enriched in   
   warm puddles -- commonly called primordial soup -- on the then lifeless   
   Earth. As the water in this soup evaporated, the concentration of urea   
   increased. Through exposure to ionising radiation such as cosmic rays,   
   it's possible that this concentrated urea produced malonic acid over   
   multiple synthesis steps. In turn, this may have created the building   
   blocks of RNA and DNA.   
      
   Why this exact reaction tool place Using their new method, the researchers   
   from ETH Zurich and the University of Geneva investigated the first step   
   in this long series of chemical reactions to find out how a concentrated   
   urea solution behaves when exposed to ionising radiation.   
      
   It's important to know that the urea molecules in a concentrated urea   
   solution group themselves into pairs, or what are known as dimers. As   
   the researchers have now been able to show, ionising radiation causes   
   a hydrogen atom within each of these dimers to move from one urea   
   molecule to the other. This turns one urea molecule into a protonated   
   urea molecule, and the other into a urea radical. The latter is highly   
   chemically reactive -- so reactive, in fact, that it's very likely to   
   react with other molecules, thereby also forming malonic acid.   
      
   The researchers also managed to show that this transfer of a hydrogen   
   atom happens extremely quickly, taking only around 150 femtoseconds,   
   or 150 quadrillionths of a second. "That's so fast that this reaction   
   preempts all other reactions that might theoretically also take place,"   
   Wo"rner says. "This explains why concentrated urea solutions produce   
   urea radicals rather than hosting other reactions that would produce   
   other molecules."  Reactions in liquids are highly relevant In the   
   future, Wo"rner and his colleagues want to examine the next steps that   
   lead to the formation of malonic acid. They hope this will help them to   
   understand the origins of life on Earth.   
      
   As for their new method, it can also generally be used to examine   
   the precise sequence of chemical reactions in liquids. "A whole host   
   of important chemical reactions take place in liquids -- not just all   
   biochemical processes in the human body, but also a great many chemical   
   syntheses relevant to industry," Wo"rner says. "This is why it's so   
   important that we have now expanded the scope of X-ray spectroscopy   
   at high temporal resolution to include reactions in liquids."  The   
   researchers from ETH Zurich and the University of Geneva were assisted   
   in this work by colleagues from Deutsches Elektronen-Synchrotron DESY   
   in Hamburg, who performed calculations required to interpret measurement   
   data.   
      
       * RELATED_TOPICS   
             o Plants_&_Animals   
                   # Genetics # Molecular_Biology # Biology   
             o Earth_&_Climate   
                   # Geochemistry # Environmental_Issues # Atmosphere   
             o Fossils_&_Ruins   
                   # Origin_of_Life # Early_Climate # Evolution   
       * RELATED_TERMS   
             o History_of_Earth o Earth o Earth's_atmosphere o Axial_tilt o   
             Timeline_of_evolution o Structure_of_the_Earth o Origin_of_life   
             o Evolution_of_the_horse   
      
   ==========================================================================   
   Story Source: Materials provided by ETH_Zurich. Original written by   
   Fabio Bergamin. Note: Content may be edited for style and length.   
      
      
   ==========================================================================   
   Journal Reference:   
      1. Zhong Yin, Yi-Ping Chang, Tadas Balčiūnas, Yashoj Shakya,   
         Aleksa Djorović, Geoffrey Gaulier, Giuseppe Fazio,   
         Robin Santra, Ludger Inhester, Jean-Pierre Wolf, Hans Jakob   
         Wo"rner. Femtosecond proton transfer in urea solutions probed by   
         X-ray spectroscopy. Nature, 2023; DOI: 10.1038/s41586-023-06182-6   
   ==========================================================================   
      
   Link to news story:   
   https://www.sciencedaily.com/releases/2023/06/230628130358.htm   
      
   --- up 1 year, 17 weeks, 2 days, 10 hours, 50 minutes   
    * Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)   
   SEEN-BY: 15/0 106/201 114/705 123/120 153/7715 218/700 226/30 227/114   
   SEEN-BY: 229/110 112 113 307 317 400 426 428 470 664 700 291/111 292/854   
   SEEN-BY: 298/25 305/3 317/3 320/219 396/45 5075/35   
   PATH: 317/3 229/426