UV Irradiation of Interstellar Medium : Production of Organic Materials

Evidence of Life in Meteorites: Origin of Life on Earth?

8th Dec 2006

Yuki Shiraji

http://www.pnas.org/cgi/reprint/98/3/815

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 http://physics.uoregon.edu/~jimbrau/BrauImNew/Chap28/FG28_02.jpg

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=800-3200)

2) Temperature = 10K

3) UV Irradiation at 2x10^15 Photons / sec (cm)

4) Irradiation Treatment for 200mins

5) Examine the Resulting RESIDUE

http://www.citycollegiate.com/benzene_orbital9.gif

Benzene

Materials

EX: Benzo[ghi]perylene

Experiment #1: Methodologies Cont.Experiment #1: Methodologies Cont.

Result of UV radiation to PAH + H20Result of UV radiation to PAH + H20

http://www.astrochem.org/PDF/Bernsteinetal1999.pdf

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

http://en.wikipedia.org/wiki/Carbonyl

http://la.wikipedia.org/wiki/Alcohol

Result: Discovery of Addition of Functional Groups to the PAH1. >C=O (Carbonyl) 2. –O-H (Hydroxy)

Experiment# 1: Examining the RESIDUE

http://www.astrochem.org/PDF/Bernsteinetal1999.pdf

Method #2: Mass Spectroscopy

Method: Compare Mass Spec. Results ofUV Radiated Benzo[ghi]pyrene And Control.

Results:- Residue from UV Radiated Sample Contain Additional Oxygen and Hydrogen Atoms

Experiment #1: Analysis of ResultsSpecies 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

http://en.wikipedia.org/wiki/Ketone

http://en.wikipedia.org/wiki/Quinone

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: 2.5--9 Times Increase in D-enriched

http://www.astrochem.org/PDF/Bernsteinetal1999.pdf

Method #2: Mass Spectroscopy

Experiment #2:

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

http://www.pnas.org/cgi/reprint/98/3/815

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.

http://fig.cox.miami.edu/~cmallery/150/memb/bilayer.jpg

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.”

http://www.pnas.org/cgi/reprint/98/3/815

Depth of Lipid Wall in Tagish Lake Meteorites =

Depth of UV penetration

(about 100-200 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 ConsiderationsFurther Considerations

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

E N D.

Thank you!

Works Cited1. Max P. Bernstein, Scott A. Sandford, Louis J. Allamandola, J. Seb Gillette,

Simon J. Clemett, Richard N. Zare, in Science 283, 5405, (1999), p. 1135-11362. Jason P. Dworkin, David W. Deamer, Scott A. Sandford, and Louis J.

Allamandola, in PNAS 98, 3, (2001), p. 815-8193. Keiko Nakamura-Messenger, Scott Messenger, Lindsay P. Keller, Simon J.

Clemett, Michael E. Zolensky, in Science 314, 5804, (2006), p. 1439-1442