Taking sides

日期:2019-03-06 11:08:04 作者:贡废 阅读:

By Joanna Marchant THE long-standing mystery about how life came to be left-handed may finally have been solved. Many molecules have alternate forms that are mirror images, like our left and right hands. Yet all life on Earth uses only left-handed amino acids to make proteins. It had been suggested that polarised light was to blame, because left and right-handed molecules absorb polarised light differently. In some reactions driven by light, this causes one form to break down faster, leaving a larger proportion of the other. But sources of polarised light in the Universe are rare (New Scientist,