Water Droplets Hold the Secret Ingredient for Building Life
Chemists uncover key to early Earth chemistry, which could unlock paths to speed up chemical synthesis for drug discovery.
Purdue University chemists have discovered a mechanism for peptide-forming reactions to occur in water — something that has baffled scientists for decades.
“This is essentially the chemistry behind the origin of life,” said Graham Cooks. He is the Henry Bohn Hass Distinguished Professor of Analytical Chemistry in Purdue’s College of Science. “This is the first demonstration that primordial molecules, simple amino acids, spontaneously form peptides, the building blocks of life, in droplets of pure water. This is a dramatic discovery.”
This water-based chemistry, which leads to proteins and ultimately to life on Earth, could also lead to the faster development of medicines to treat humanity’s most debilitating diseases.
Scientists have theorized for decades that life on Earth began in the oceans. However, the chemistry behind this remained an enigma. Raw amino acids — something that meteorites delivered to early Earth daily — can react and latch together to form peptides. These are the building blocks of proteins and, eventually, life. Strangely, the process requires the loss of a water molecule, which seems exceedingly improbable in a wet, aqueous, or oceanic environment. For life to form, it required water. However, it also needed space away from the water.
Cooks, an expert in mass spectrometry and early Earth chemistry, and his research team have uncovered the answer to the riddle: “Water isn’t wet everywhere.” On the margins, where the water droplet meets the atmosphere, extremely quick reactions can take place, transforming abiotic amino acids into the building blocks of life. Therefore, fertile landscapes for life’s potential evolution were in places where sea spray flies into the air and waves pound the land, or where fresh water burbles down a slope.
“The rates of reactions in droplets are anywhere from a hundred to a million times faster than the same chemicals reacting in bulk solution,” Cooks said.
The swift rates of these reactions make catalysts unnecessary, speeding up the reactions and, in the case of early Earth chemistry, making the evolution of life possible. Decades of scientific investigation have been focused on figuring out how this mechanism works. The secret of how life emerged on Earth can help scientists better understand why it happened and guide their search for life on other planets, or even moons.
Understanding how amino acids built themselves up into proteins and, eventually, life forms revolutionizes scientists’ understanding of chemical synthesis. That same chemistry may potentially help synthetic chemists identify and create novel medications and therapeutic treatments for illnesses by accelerating key processes.
SciTech Daily
The process is familiar by now: Show something slightly new in chemistry, wildly extrapolate its significance to the media, and make an extravagant claim suggesting that we now see how life can arise naturally.
The article said: “Chemists discover a mechanism for peptide-forming reactions to occur in water, which leads to proteins and so to life on Earth.” Peptides are short chains of amino acids; proteins are composed of much longer chains of amino acids. But for life, the specific sequence of amino acids in a protein is essential for it to fold properly into a functional three-dimensional configuration. The requirement of a particular sequence of amino acids endows the protein with vast amounts of information, far beyond what could be “chanced upon” by any natural process within the history of the entire universe. The superficial gloss of the article is promoting scientific nonsense.