8.9 +/- 0.1, while compound V had a pKa of 11.1 +/- 0.2. Origins of Homochirality on Prebiotic Earth The essential building blocks of life (amino acids and key sugars-ribose and deoxyribose) can exist in one of two forms-L or D. However life has evolved such that the vast majority of amino acids are L and the sugars are D. If the amino acids and sugars present in life were racemic (consisting of both L and D), then proteins, DNA, and RNA would not adopt a well defined conformation, resulting in a loss of function. The question of how this preference first occurred has puzzled scientists for years while several theories have been proposed; there is still no clear answer. There is growing evidence that the chiral preference came from outer space as scientists discovered α-methyl amino acids inside the Murchison meteorite that have a slight enantiomeric excess (ee) for the L conformation. These α-methyl amino acids are believed to be from outer space as a result of their high abundance of 13C and deuterium. Furthermore, α-methyl amino acids are generally not present in terrestrial chemistry. A common critique is that these amino acids would not be able to tolerate the high temperatures upon entering earth's atmosphere as the meteorite crashed into the planet. However, the amino acids have been found inside the meteorite, with the meteorite acting as an insulator. Unlike regular amino acids, α-methyl amino acids are not capable of racemizing by enolization on an evolutionary time scale, shown below. However, there is considerable debate as to how the L conformation of α-methyl amino acids was selected for. The most widely accepted theory is that right circularly polarized light in outer space (somewhat) selectively destroyed the D conformation. In theory, synchrotrons produce light of opposite handedness (right and left) above and below the circulation plane. This has been demonstrated in experiments on earth. The theory continues then that neutron stars could act as synchrotrons-with right polarized light pointing in our direction of the universe, and left polarized light pointing in the opposite direction. However, other astronomers claim that the polarization only occurs in the infrared region, which only has sufficient energy to cause molecular vibrations and stretches-far from being capable of destroying molecules. A second problem encountered with the L α-methyl amino acids is how to generate enantiomerically pure regular amino acids from the slight excess. The issue