Enantiomeric separation of complex organic molecules produced from irradiation of interstellar/circumstellar ice analogs(NOT OPEN ACCESS)
SUMMARY: To simulate conditions in space and in asteroids and meteorites, scientists put simple gases (water, carbon dioxide, ammonia, and methanol) into a low temperature and low pressure chamber. Then, using UV light, they irradiated these gases (which at the low temps turned into ice), brought everything back to room temperature, and looked at the residues that were left. They found (using a mass spectrometer) various types of simple amino acids in the residues (glycine, alanine, valine) and other amino acids not used to make proteins in living organisms.
LESSON COMMENTS: You don’t need a lot of organic chemistry background to understand this article and students should have an easy time understanding what is happening after a brief lesson on basic organic chemistry concepts.
The concept of chirality and enantiomers are addressed in this article and is a good way to teach students about enzyme specificity and why certain macromolecules are not recognized by the body (example: trans vs cis fats, L and D amino acids, cellulose vs starch).
The mass spectrometer and how it functions is way to connect physics with chemistry. There are also various types of mass specs out there. A good research activity for students would be to research how the machines are different and why some are preferred over others in a specific experiment. What would that experiment be about?
Nuevo, M., Meierhenrich, U., D’Hendecourt, L., Caro, G. M., Dartois, E., Deboffle, D., Thiemann, W.H.-P., Bredehoft, J.-H., Nahon, L. (2007). Enantiomeric separation of complex organic molecules produced from irradiation of interstellar/circumstellar ice analogs. Advances in Space Research,39(3), 400-404. doi:10.1016/j.asr.2005.05.011