Transcript Experiment #1: Analysis of Results

Evidence of Life in Meteorites:
Origin of Life on Earth?
UV Irradiation of
Interstellar Medium :
Production of Organic
Materials
http://www.pnas.org/cgi/reprint/98/3/815
8th 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
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.”
Experiments Done by Scott A. Standford et al:
UV Irradiation of Simulated Interstellar Medium
Resulted in…
1)Creation of Alcohols, Quinones, and Ethers.
2) Creation of Membrane-like Droplets.
PAH = Polycyclic Aromatic Hydrocarbons
Experiment #1:
PAH + H20 + UV Irradiation
Results in the Production
of Alcohols, Quinones, and
Ethers
Experiment#1: Materials and Methods
Materials
Benzene
EX: Benzo[ghi]perylene
http://www.citycollegiate.com/benzene_orbital9.gif
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
Experiment #1: Methodologies Cont.

Result of UV radiation to PAH + H20
http://www.astrochem.org/PDF/Bernsteinetal1999.pdf
Experiment #1: Examining the Residue
Method #1: Infrared
spectroscopy
Result: Discovery of Addition of
Functional Groups to the PAH
1. >C=O (Carbonyl)
2. –O-H (Hydroxy)
Significance of Results:
http://en.wikipedia.org/wiki/Carbonyl
http://la.wikipedia.org/wiki/Alcohol
Starting Material: PAHs  Stable, Refractory, Unreactive
Resulting Product: Functional groups  Gain of Reactive Nature
the Ability of the Molecule to React with Other Nucleophiles
Experiment# 1: Examining the RESIDUE
Method #2: Mass Spectroscopy
Method: Compare
Mass Spec. Results of
UV Radiated
Benzo[ghi]pyrene And
Control.
http://www.astrochem.org/PDF/Bernsteinetal1999.pdf
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:
http://en.wikipedia.org/wiki/Ketone
Ex) Ketone
+
http://en.wikipedia.org/wiki/Quinone
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:
Method #2: Mass Spectroscopy
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 Denriched
http://www.astrochem.org/PDF/Bernsteinetal1999.pdf
Experiment #2:
http://www.pnas.org/cgi/reprint/98/3/815
Gas-Mixture (H2O, CH3OH, NH3, CO)
+ UV Irradiation Results in
the Production of
Membrane-like Organic
Droplets
Experiment#2: Materials and Methods
Materials
Emulated Interstellar Gas-Mixture:
H2O, CH3OH, NH3, CO
Methodology
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)
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
http://fig.cox.miami.edu/~cmallery/150/memb/bilayer.jpg
Experiment #2: Analysis of Droplet Structures
Method: Fluorescent Experiment
Hollow Structure Inside of droplets??
 YES!
http://www.pnas.org/cgi/reprint/98/3/815
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 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
+
Also in Reality,
Organic Materials Are Discovered in Meteorites,
↓
Justifies the Hypothesis:
“Life on Earth Originated in Space ,
Reaching to Earth via 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. 1135-1136
2. Jason P. Dworkin, David W. Deamer, Scott A. Sandford, and Louis J.
Allamandola, in PNAS 98, 3, (2001), p. 815-819
3. Keiko Nakamura-Messenger, Scott Messenger, Lindsay P. Keller, Simon J.
Clemett, Michael E. Zolensky, in Science 314, 5804, (2006), p. 1439-1442