Scientists have discovered how a chemical in the cells of marine organisms allows them to survive the high pressures in the deep oceans.
The deeper sea creatures live, the more inhospitable and extreme the environment they have to deal with. At one of the deepest points in the Pacific Ocean — the Mariana Trench, 7 miles (11 kilometers) below the sea’s surface — the pressure is 1.1 kbar, or eight tons per square inch. That’s a 1,100-fold increase in the pressure experienced at the Earth’s surface.
Under normal or atmospheric pressure, water molecules form a tetrahedral network.
Network of water molecules changes shape
However, at high pressure, the network of water molecules begins to deform and change shape. When this happens to the water in living cells, it prevents vital biochemical processes from taking place – and kills the organism.
By reporting their findings, the Leeds researchers have been able to explain for the first time how a molecule found in the cells of marine organisms counteracts the effect of external pressure on the water molecules.
Professor Lorna Dougan, from the School of Physics and Astronomy in Leeds, said: “Life has adapted to survive and thrive in extreme environments. In the depths of the oceans, organisms live under extremely high pressures that would destroy human life. .
“These high pressures distort the liquid water present in all life, resulting in deleterious effects on the biomolecules underlying all biological processes.
“We need to understand what happens to water under pressure and how pressure-adapted organisms counter these effects. If we can understand how these organisms survive under extreme pressure, we can apply these findings to the broader study of biomolecular stability.”
Trimethylamine N-oxide or TMAO
The molecule found in cells that produces the protective effect against high external pressure is called TMAO – trimethylamine N-oxide. Studies have shown that the amount of TMAO in ocean-dwelling organisms increases with the depth of their habitat.
Led by Dr. Harrison Laurent, also of the School of Physics and Astronomy, the study used one of the most advanced analytical facilities in the world to examine how intense pressure changes the hydrogen bonds between neighboring water molecules.
The analytical facility at the STFC Rutherford Appleton Laboratory in Oxfordshire, called the ISIS Neutron and Muon Source, was used to fire a beam of neutrons — these are subatomic particles — at water samples with and without TMAO. The analysis was done at low pressure, 25 bar, and at high pressure, 4 kbar.
The test revealed details of the atomic structure of the water molecules.
At high pressure, the hydrogen bonds in the pure water sample were deformed and less stable and the total network of water molecules was densified.
However, the presence of TMAO enhanced and stabilized the hydrogen bonding and maintained the network structure of the water molecules.
dr. Laurent said: “The TMAO provides a structural anchor that allows the water to withstand the extreme pressures under which it stands. The findings are important because they help scientists understand the processes by which organisms have adapted to survive the extreme conditions found in the oceans.”
From the study, the research team has also been able to develop a so-called “osmolyte-protection ratio”, which predicts the level of TMAO needed in the cells of marine organisms so that they can survive at a specific depth in the oceans. .
Professor Dougan added: “Professor Dougan added: “Our study bridges the gap between water under pressure at the molecular level and the prodigious ability of organisms that thrive under high pressure in the depths of the oceans.
“Recently published research has revealed new species that live at the bottom of the deep seas. We now understand the remarkable adaptations that have allowed life to exploit these habitats.”
The scientific article – “The ability of trimethylamine N-oxide to resist pressure-induced disturbances of the water structure” – has been published in the scientific journal Communication Chemistry.
The role of solvents in extreme pressure
The ability of trimethylamine N-oxide to resist pressure-induced disturbances of the water structure, Communication Chemistry (2022). DOI: 10.1038/s42004-022-00726-z , www.nature.com/articles/s42004-022-00726-z.
Quote: Chemical in cells of marine organisms allows them to survive high pressure in deep oceans (2022, September 28) retrieved September 28, 2022 from https://phys.org/news/2022-09-chemical-cells- marine-enables- survive.html
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