UCF AVS Astrochemistry Webinar: Dr. Christopher Materese скачать в хорошем качестве

UCF AVS Astrochemistry Webinar: Dr. Christopher Materese

Formation and destruction of nucleobases in ices Nucleobases are important building blocks of RNA and DNA for all known organisms and determining their abiotic origins may be important to understanding the emergence of life. It has been hypothesized that many of the building blocks of life may have extraterrestrial origins that could be traced back to low temperature radiolysis and photolysis of interstellar ices. Here, we will discuss the use of laboratory experiments to study the formation of all of the five primary nucleobases (cytosine, uracil, thymine, adenine, and guanine) through the UV photolysis of ices containing pyrimidine and purine. We will also discuss the formation of nitrogen- and oxygen-aromatic heterocycles from the irradiation of aromatic hydrocarbons in ices. Finally, determining the radiolytic stability of nucleobases is also important for understanding the range of icy environments in which nucleobases from both abiotic and biogenic sources may persist. To that end, we will address the radiation stability of thymine and thymine mixed with water ice over a range of temperatures and concentrations. Speaker Biography: Dr. Christopher Kroboth Materese is a Research Scientist in the Cosmic Ice Lab at NASA Goddard Space Flight Center. He earned a B.S. in chemistry from the Pennsylvania State University in 2005 and he completed his Ph.D. in chemistry, with a focus on Computational Biophysics, at the University of North Carolina at Chapel Hill in 2010. Later in 2010 he began work as a Postdoctoral Researcher in the Astrochemistry Lab at the NASA Ames Research Center. Thursday, June 18, 2020