26/08/2026
Origin of Amino Acids
Amino acids originated on early Earth through abiotic (non-living) chemical synthesis from simple atmospheric gases or via delivery from extra terrestrial impacts like comets and meteorites.
Theories of Origin
• Primordial Soup & Miller-Urey: Classic experiments demonstrated that electric sparks passing through a simulated primitive atmosphere of methane, ammonia, hydrogen, and water v***r can spontaneously synthesize basic amino acids like glycine and alanine.
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• Extraterrestrial Delivery: Carbonaceous meteorites, such as the Murchison meteorite that fell in Victoria, Australia, contain dozens of amino acids, supporting the idea that space rocks supplied organic building blocks to the early Earth.
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• Hydrothermal Vents: Mineral-rich and energy-dense environments on the ocean floor may have catalyzed the chemical reactions needed to form early organic monomers.
Evolution of the Biological Set
• Standard 20: Life eventually selected a small, highly functional subset of 20 to 22 standard amino acids out of hundreds of structurally possible variants for protein synthesis.
• Metabolic Integration: This selection was driven by chemical stability, accessibility through primitive metabolic pathways, and the ability to spontaneously link into peptide chains.