New Discovery Sheds Light on Origin of Left- and Right-Handed Molecules in Life
Researchers propose that magnetic minerals common on early Earth could have caused key biomolecules to accumulate on their surface in just one mirror image form, setting off a positive feedback that continued to favor the same form, explaining the origin of biological handedness or "homochirality." The researchers found that when they exposed the magnetite surface to a solution containing an equal mix of right- and left-handed RAO molecules, 60% of those that settled on top were of a single handedness. Once an excess of chiral RNA is formed, known chemical reactions could pass on this chiral bias, templating amino acids and proteins with the opposite handedness and ultimately fostering other chiral molecules essential to cell metabolism.