If you believe the films about monsters and old scientific experiments, life began with a spark. Not everyone believes in this story about the origin of life, so they continue to look for sources of energy that can turn prebiotic broth into a life-giving dish. It may be that the secret ingredient is just a pinch of salt. In any case, it can be assumed, starting from a new study conducted by scientists from the Institute of Earth Science and Life (ELSI) at the Tokyo Institute of Technology in Japan.
Scientists have drawn attention to the usual and well-known sodium chloride as a potential conductor of chemical energy necessary for early biochemistry. Sodium chloride consists of a 1: 1 ratio of sodium ions and chlorine, and in this case chlorine ions will be the culprits. As soon as they receive a dose of intense electromagnetic radiation, everything begins.
Does life need ordinary salt?
The origin of life on Earth has always been of interest to people.
Science explains well how life has evolved and evolved to such a degree of diversity. We can use explanations like natural selection to get to what we have today.
At some point, we need to move from the chaotic vortex of organic chemicals to imperfect code replications, which can be seen as the very first glimpse of life; the first ecosystem, as required by the RNA-world hypothesis.
Unfortunately, in this hypothesis there is a problem of chicken and eggs.
Life depends on the consumption of energy from one source — whether chemical bonds or sunlight — and using it to rearrange compounds. Without an energy source, we could not hasten the production of basic chemicals, from which primitive genetic codes are then compiled.
Although all modern organisms inherit the necessary cellular device, the first metabolic jump had to rely on a fairly common source of energy. So that it is easier to find it not in life, but in the environment.
In the early 1950s, two chemists, Stanley Miller and Harold Urey, interestingly generated a number of amino acids from simple materials, demonstrating for the first time that basic substances for proteins do not necessarily need a living source.
They energized the environment, suggesting that the early Earth generously received lightning strikes, and therefore energy.
But despite the fact that this process actually produced amino acids, RNA consists of a different alphabet of basic chemicals. Attempting to understand how they formed, also resulted in an energy problem.
Last year, a group of scientists suggested that plasma from shock waves propagating from the site of an asteroid’s fall could provide enough energy to transform organic building blocks into formamide — the parent molecule for four letters of RNA.
Well, in part, these rare events – the strikes of asteroids and lightning – can explain the production of a small number of key players. Meanwhile, there are a number of other chemicals that might have supporting roles and that also need to be explained.
The new study retreats a bit to include the story of a wider troupe of actors who might be important in a chain of life-forming reactions. One such example is the compound cyanamide.
Earlier works by other scientists have identified ways to create fundamental starting blocks of RNA from compounds like hydrogen cyanide in the presence of almost one UV light. But for this it was necessary to form cyanamide, and no one could do this.
“Our goal, respectively, was to develop a network of reactions that produce simple sugars, including cyanamide, and other important precursors for RNA synthesis in one pot, the scientists write.
After analyzing the reaction chains supported not by ultraviolet light, but by more intense gamma radiation, they noticed that cyanamide levels increased in proportion to rather unexpected reagents – chlorine ions.
Of the two components contained in salt, it is sodium that usually attracts the most attention, and its chloride satellite, which rarely participates in reactions, is usually overlooked.
Apparently, gamma irradiation weakens the chloride electrons and provides a burst of energy necessary for the formation of cyanamide. In a sense, it sounds more complicated (and less exciting) than lightning strikes and falling asteroids. But life did not have to start with a boom.
Perhaps it began with a pinch of spices.