UV Irradiation of Interstellar Medium : Production of Organic Materials Evidence of Life in Meteorites: Origin of Life on Earth? 8 th Dec 2006 Yuki Shiraji

Current Common Theory: Chemical Evolution Creation of Amino Acids from Inorganic Material Miller-Urey Experiment: Electric Discharge Methods Using Alternative Energy Sources: -Heat -Gamma rays -Infrared rays -Ultraviolet rays

Scott A. Standford et al.: Creation of Organic Materials under Their Emulated Interstellar Environment. + Similar Organic Materials Have Been Discovered in Meteorites. ↓ Hypothesis: “ Organic Materials Created in the Space Were Brought to the Earth via Meteorites Which Was the Point of Origin of Life on Earth.”

UV Irradiation of Simulated Interstellar Medium Resulted in… 1)Creation of Alcohols, Quinones, and Ethers. 2) Creation of Membrane-like Droplets. Experiments Done by Scott A. Standford et al :

Experiment #1: PAH + H20 + UV Irradiation Results in the Production of Alcohols, Quinones, and Ethers PAH = Polycyclic Aromatic Hydrocarbons

Experiment#1: Materials and Methods Methodology 1) H2O + PAHs  compressed into Ice particle, (H2O/PAH= ) 2) Temperature = 10K 3) UV Irradiation at 2x10^15 Photons / sec (cm) 4) Irradiation Treatment for 200mins 5) Examine the Resulting RESIDUE Benzene Materials EX: Benzo[ghi]perylene

Experiment #1: Methodologies Cont. Result of UV radiation to PAH + H20 Result of UV radiation to PAH + H20

Experiment #1: Examining the Residue Method #1: Infrared spectroscopy Significance of Results: Starting Material: PAHs  Stable, Refractory, Unreactive Resulting Product: Functional groups  Gain of Reactive Nature; the Ability of the Molecule to React with Other Nucleophiles Result: Discovery of Addition of Functional Groups to the PAH 1. >C=O (Carbonyl) 2. –O-H (Hydroxy)

Experiment# 1: Examining the RESIDUE Method #2: Mass Spectroscopy Method: Compare Mass Spec. Results of UV Radiated Benzo[ghi]pyrene And Control. Results: - Residue from UV Radiated Sample Contain Additional Oxygen and Hydrogen Atoms

Experiment #1: Analysis of Results Species Found in the Residue Belong to a Class of Molecules that Are Necessary Organic Compounds for Primordial Life: Ex) Ketone + Quinones: Made from Ketone Precursors. Quinones Are Crucial for Electron Transport in Simple Organisms

Experiment #1: Analysis of Results Mass Spec. of Corene (another type of PAH) shows Increased Deuterium Enrichment: This Enrichment Profile Is Consistent with that of Organic Globules Found in Meteorites Ex). Organic Globules Found in Tagish Meteorites: Times Increase in D- enriched Method #2: Mass Spectroscopy

Experiment #2: Gas-Mixture (H2O, CH3OH, NH3, CO) + UV Irradiation Results in the Production of Membrane-like Organic Droplets

Experiment#2: Materials and Methods 1)Gas-mixture: H2O, CH3OH, NH3, CO (ratio of 100:50:1:1) was compressed into ice particle 2) Temperature = 15K 3) UV irradiation at 10^15 photons/sec 4) Isolate membrane-like materials  use HPLC (High Performance Liquid Chromatography) 5) Examine the RESIDUE (droplets) Methodology Materials Emulated Interstellar Gas-Mixture: H2O, CH3OH, NH3, CO

Experiment #2: Observations, Data Results and Anaylsis Observations -Starting Gas-Mixture (H2O, CH3OH, NH3, CO) Was Mostly Polar = Water Soluble. -But Droplets  Water Insoluble This INDICATES That, the Subunit Components Making Up the Lipids Found Are Amphiphilic -Have Both Polar and Non-Polar Characteristic -Have Both Hydrophilic and Hydrophobic. Conclusion: UV Irradiation Caused the Formation of Amphiphilic Molecules

Experiment #2: Analysis of Droplet Structures Method: Fluorescent Experiment Hollow Structure Inside of droplets??  YES! Explanation for This Finding: Nakamura : “Formation of Lipid Wall  Prevents Further UV to Reach Inside.” Depth of Lipid Wall in Tagish Lake Meteorites = Depth of UV penetration (about nm)

*Conclusion* 1)UV Irradiation on emulated Interstellar PAHs Creates Complex Organic Compounds Crucial for Primordial Life on Earth (Such As Alcohols, Quinones, Ethers, etc), 2) UV Irradiation on Emulated Interstellar Gas-Mixture (H2O, CH3OH, NH3, CO) Creates Membrane-like Vesicle Droplets Which Highly Resemble Membranes Found in All Cells Today.

So, Now It Is Proven That Organic Materials Found on Earth Can Be Created in an Artificial Interstellar Medium ↓ Justifies the Hypothesis: “Life on Earth Originated in Space, Reaching to Earth via Meteorites” + Also in Reality, Organic Materials Are Discovered in Meteorites,

Further Considerations Organic Droplets Could Potentially Be the Precursors to the Very First Cells that Existed.

E N D. Thank you! Works Cited 1. Max P. Bernstein, Scott A. Sandford, Louis J. Allamandola, J. Seb Gillette, Simon J. Clemett, Richard N. Zare, in Science 283, 5405, (1999), p Jason P. Dworkin, David W. Deamer, Scott A. Sandford, and Louis J. Allamandola, in PNAS 98, 3, (2001), p Keiko Nakamura-Messenger, Scott Messenger, Lindsay P. Keller, Simon J. Clemett, Michael E. Zolensky, in Science 314, 5804, (2006), p