Amino Acids and the Asymmetry of Life (eBook)

Foreword 7
Preface 10
Contents 13
List of Symbols and Abbreviations 16
Chapter 1 Tracing Life’s Origin: From Amino Acids to Space Mission ROSETTA 20
1.1 The Origin of Life 20
1.2 The Asymmetry of Life 21
1.3 How Life’s Asymmetry Originated 24
Chapter 2 Stereochemistry for the Study of the Origin of Life 36
2.1 Amino Acids and Chemical Reactions: A Guided Tour 36
2.2 Optical Activity 43
2.3 Stereochemical Nomenclature 44
2.3.1 The Cahn-Ingold-Prelog Notation: R- and S-Enantiomers 44
2.3.2 (+)- and (–)-Enantiomers 45
2.3.3 D- and L-Enantiomers 45
2.3.3 D- and L-Enantiomers 45
2.3.4 d- and l-Enantiomorph Crystals 46
2.3.5 P- and M-Descriptors 46
2.3.6 .- and .-Descriptors 46
2.4 Optical Rotation Dispersion and Cotton Effect 47
2.5 Through the Eye of a Chromophore: CD Spectroscopy 50
2.6 Miscellaneous Techniques 53
2.7 “Chiral Light” and the Stokes Parameters 55
2.8 Chromatographic Resolution of Enantiomers 58
Chapter 3 Minority Report: Life’s Chiral Molecules of Opposite Handedness 66
3.1 Sympathy for the Devil: How D-Amino Acids Make OrganismsWork 67
3.2 The Dark Side of D-Amino Acids 70
3.3 “What Time was it?” Ask the Amino Acid Clock! 71
3.4 Biotic Origin:Were D-Life and L-Life Contemporaries? 73
Chapter 4 When Crystals Deliver Chirality to Life 79
4.1 Spontaneous Crystallization of Chiral Minerals 81
4.2 Heated Debate:Which Amino Acid Enantiomer Precipitates First? 85
4.3 TurningWorld: The Direction of Stirring 90
4.4 Deposits of Enantiomorphous Quartz on Earth 92
4.5 Adsorption of Chiral Organic Molecules on Enantiomorphous Crystals 94
Chapter 5 When Parity Falls: TheWeak Nuclear Interaction 97
5.1 The Fall of Parity: “I Couldn’t Understand It” 98
5.2 Asymmetric Radiolysis by Polarized Electrons 102
5.3 The Vester-Ulbricht Process 104
5.3.1 Circularly Polarized Bremsstrahlung in the VU Process 105
5.3.2 In Search of the Ultimate VU Experiment: California Dreaming? 106
5.3.3 What Are the Next VU Experiments? 108
5.4 Parity Non-Conserving Energy Differences 108
5.4.1 The Electroweak Interaction 109
5.4.2 Characteristics of Electromagnetic and Weak Interaction 110
5.4.3 Difference Matters: Energies of Enantiomers 111
5.4.4 Calculated Energy Differences of Amino Acid Enantiomers 113
5.4.5 Calculated Energy Differences of Sugar Enantiomers 115
5.4.6 Never Say Never: Measuring Parity Non-Conserving Energy Differences 117
5.4.7 Implications of Parity Non-Conserving Energy Differences 120
Chapter 6 Chiral Fields: Light, Magnetism, and Chirality 121
6.1 Magneto-Optical Effects 122
6.2 Photochirogenesis 125
6.2.1 Asymmetric Photolysis of Racemic Organic Molecules 125
6.2.2 Asymmetric Photolysis of Amino Acids 126
6.2.3 Asymmetric Photoisomerization 135
6.2.4 Asymmetric Synthesis 137
6.2.5 ‘Natural’ Sources of Circularly Polarized Light 138
Chapter 7 Key to the Prebiotic Origin of Amino Acids 143
7.1 Amino Acid Formation Under Atmospheric Conditions 143
7.2 Amino Acid Formation Under Hydrospheric Conditions 145
7.3 Amino Acid Formation Under Interstellar Conditions 145
7.3.1 Photochemistry in the Interstellar Medium 145
7.3.2 Simulation of Interstellar Chemistry in the Lab 146
7.3.3 Fresh in the Ice: Amino Acid Structures 149
7.3.4 Illumination with Circularly Polarized Light 158
Chapter 8 A New Record for Chiral Molecules in Meteorites 162
8.1 Chiral Organic Molecules in Meteorites? 162
8.1.1 Amino Acids in Meteorites 163
8.1.2 The Untold Story of Diamino Acids in Meteorites 165
8.2 Diamino Acids as Gene Trigger 171
8.3 Survival of Organic Molecules After Impact on Earth 174
8.4 Space Exploration and Chirality: What Next? 175
Chapter 9 The New Space Race: Chiral Molecules on Comets and on Mars 177
9.1 In Search of Chiral Molecules in Comets 177
9.2 Chiroptical Techniques and the SETH Project 194
9.3 The Search for Chiral Molecules on Mars 195
Chapter 10 Accelerating the Carousel: Amplification Mechanisms 200
10.1 Some Amplification Needed: The Bifurcation Theory 202
10.2 Amplification by Kinetic Reaction Sequences 204
10.3 Amplification by Progressive Accumulation 209
10.4 Amplification by the Soai Reaction 210
10.5 Transfer, Memory, and Switching of Chiral Properties 212
10.6 Concluding Remarks 213
Appendix 214
Bibliography 221
Index 243