Thymine and Other Prebiotic Molecules Produced from the Ultraviolet Photo-Irradiation of Pyrimidine in Simple Astrophysical Ice Analogs(NOT OPEN ACCESS)
SUMMARY: In the second edition of beaming pyrimidines, instead of using ammonia, scientists beamed pyrimidines with methanol, water and methanol, methane, and water and methane, at various ratios for each combination. As with “Beaming Pyrimidines Part 1”, the gases were cooled way down (15-25K) in a low pressure chamber, turned into ice at those low temperatures, and then beamed with photons from a UV lamp. These photons (as well as the low temperature and pressure) are supposed to be similar to the environment in an asteroid. After beaming anywhere from a day to 3 days, the samples were warmed up to 220K and analyzed. The products that were identified are on Table 2; the reader should be aware that there were many other products that could not be identified. Scientists are most interested in the production of molecules such as thymine, urea, glycine, and others because they are found in living organisms on Earth.
LESSON COMMENTS: The Beaming Pyrimidines series is most useful when teaching students about the scientific method. This series of experiments show the small changes scientists make to one experiment. The same concepts of chemistry, organic chemistry, and physics can be applied to the entire series. One of the most beneficial things about reading this series is the application of these same topics over and over in actual experiments. Teachers can prepare students by supplementing this series with lessons on DNA, RNA structure and organic chemistry functional groups.
Materese, C. K., Nuevo, M., Bera, P. P., Lee, T. J., & Sandford, S. A. (2013). Thymine and Other Prebiotic Molecules Produced from the Ultraviolet Photo-Irradiation of Pyrimidine in Simple Astrophysical Ice Analogs. Astrobiology,13(10), 948-962. doi:10.1089/ast.2013.1044