Scientists have created a chemical reaction using cyanide that could have led to the formation of organic life on Earth four billion years ago.
Known as a deadly chemical that can exist in many different forms, cyanide has seeped into popular culture over the years through movies and fiction. Karen Smith, a senior research scientist at Boise State University, noted a few years ago: “When most people think of cyanide, they think of spy movies – a guy who swallows a pill, foams at the mouth and dies, but it’s probably cyanide that’s a key compound for building molecules.” essential to life.”
In fact, new research has found that the deadly compound could, in fact, help life evolve on Earth.
Moreover, searching for signs of it on alien planets may help us locate life elsewhere in the universe, as the chemists at Scripps Research have found.
The team discovered that the compound, which contains a carbon atom bonded to a nitrogen atom, could have enabled some of the first metabolic reactions on Earth that created carbon-based compounds from carbon dioxide. Metabolic reactions are the reactions that generate energy from food and are necessary to sustain life.
“Cyanide may have played a key role in the origins of life on Earth,” the researchers told BBC Science Focus in its article.
Dr. Ramanarayanan Krishnamurthy, Scripps Research Associate Professor of Chemistry and lead author of the study said: ‘When we look for signs of life – either on early Earth or on other planets – we base our search on the biochemistry we know exists in life today. And the fact that these metabolic reactions It could be driven by cyanide showing that life could be completely different.”
To make this discovery, the team focused on a set of chemical reactions that combine carbon dioxide and water.
The intention was to create more complex compounds essential for life known as reverse carboxylic acid, or r-TCA cycle.
The cycle is used by some of the bacteria currently on Earth. But it relies on the use of complex proteins that were not yet formed on the planet four billion years ago.
Previous studies have shown that some metals can perform the same reactions under extremely hot and extremely acidic conditions.
But Scripps’ team has a hunch that another chemical compound might also be able to do this, only under the least dangerous conditions seen on early Earth.
Since they already knew cyanide was present in the atmosphere at the time, they were able to plot a set of reactions that could use cyanide to produce more complex organic molecules from carbon dioxide, and then test them later in the lab.
Dr Krishnamurthy said: ‘We didn’t have to do anything special, we mixed these molecules together, we waited and the reaction happened spontaneously.’
Unfortunately, the experiment does not provide conclusive evidence that cyanide was involved in this process on early Earth. But it offers a new way of thinking about the origin of life.
According to the researchers, it may provide a new way to search for life on other planets.