Special Issue "Symmetry of Life and Homochirality"
A special issue of Symmetry (ISSN 2073-8994).
Deadline for manuscript submissions: closed (28 February 2010)
Prof. Dr. David Cline (Website)
Physics & Astronomy Department, College of Letters & Sciences, UCLA, 3-166 Knudsen Hall, Box 951547, Los Angeles, CA 90095-1547, USA
Interests: astroparticle physics; solar neutrino puzzle and nucleon decay; unique detection of primordial black holes; gamma-ray astronomy
In 1848 L. Pasteur carried out one of the most important experiments in Life Sciences when he transmitted polarized light through a medium with crystal found near a wine producing facility. These crystals were large enough that the individual symmetry (or resolution) of the crystal could be determined. He discovered that these biological materials caused polarized light to have its plane rotated (or optical activity). Two key results come from this experiment:
(a)-Biological materials are built out of 3-dimensional molecules (stereo
(b)-Most of the key molecules in life are either left-handed or D (right-handed)
We now know that 19 of the 20 Amino Acids that make proteins in life are left-handed. This is sometimes called Chiral Symmetry breaking or Homochirality.
In the physical world the concepts of Symmetry and Symmetry breaking are of key importance, while Symmetry principles are key to important physical theories (i.e. Lorentz Invariance and the Theory of Relativity). Asymmetry comes into the nature of the weak force (that drives the energy production in the sun). This depends on a symmetry breaking that leads to a massive particle the Z° with the same properties as the photon of liquid but is 90 proton masses heaver.*
Some Biologists believe that the very existence of life depends on the chiral symmetry breaking or Homochirality; therefore, understanding the origin of this aspect of life could be related to the understanding of the origin of life to some.
*The author was part of the team that in 1983 discovered the Z° particles at Geneva, Switzerland.
Prof. Dr. David Cline