<< When holding a right hand in front of a mirror, one can see a reflected image of a left hand and vice versa. In 1848, Louis Pasteur discovered that organic molecules are much like our hands: they come in mirror-image pairs of left- and right-handed variants. Nowadays, we know that this handedness or chirality (from the Greek word for "hand") is a hallmark of organic molecules. >>
<< Organic molecules are rich in carbon atoms, which form bonds to create either a right or a left "nano-hand." Yet, puzzlingly, life almost always selects to exclusively use one of the two mirror-image twins—a phenomenon called homochirality. For example, terrestrial life is based on left-handed amino acids and right-handed sugars. >>️️
<< A model now proposes a novel explanation for the emergence of homochirality in life—a longstanding puzzle about the origin of life on Earth. >>️
<< Homochirality emerges spontaneously in prebiotic chemical networks that adapt to optimize energy harvesting from the environment. Previously, it was believed that chiral symmetry breaking requires multiple loops of auto-catalysis, which increasingly produces one enantiomer of a molecule while inhibiting the formation of the other. However, the IBS team's results showed that the underlying mechanism of symmetry breaking is very general, as it can occur in large reaction systems with many random molecules and does not require sophisticated network architectures. It was found that this sharp transition to homochirality stems from the self-configuration of the reaction network in order to achieve more efficient harvesting of energy from the environment. >>️
Learning chemical networks give life a chiral twist. Institute for Basic Science. Apr 26, 2022.
William D. Pineros, Tsvi Tlusty. Spontaneous chiral symmetry breaking in a random driven chemical system. Nat Commun 13, 2244. doi: 10.1038/ s41467-022-29952-8. Apr 26, 2022.
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Keywords: evolution, gst, randomness, self-assembly, self-configuration, break symmetry, asymmetry, chiral, chirality
