Photobiology, Ionizing Radiations

General Preface

Preface to Section V

Chapter I. Phototropism

1. Introduction

2. Types of Phototropic Response

a. Higher Plants

b. Lower Plants

3. The Photoreceptors

a. Action Spectra in the Visible

b. Action Spectra in the Further Ultraviolet

c. Effects of Red Light

d. Deductions as to the Chemistry of Photoreceptors

e. Evidence as to the Localization of Photoreceptors

4. The Effector System

a. The System in Higher Plants

b. The Role of Auxin Destruction in Phototropism

c. Relation Between Phototropism and Light Growth Reactions

References

Chapter II. Biochemistry of Visual Processes

1. Structure and Light-Absorbing Properties of the Photoreceptor Cells

2. Visual Pigments in Solutions

3. Absorption Spectra

4. Chemical Nature of the Rhodopsins

5. The Porphyropsins

a. Chemical Basis and Cis-Trans Isomerism

b. Absorption Properties

6. Other Chromophores

7. Varieties and Distribution of Rhodopsins and Porphyropsins

8. Preliminary Remarks on Visual Pigment Structure

9. The Photoproducts

a. Prelumirhodopsin

b. Lumirhodopsin

c. Metarhodopsin

10. Structure of the Photoproducts and Further Remarks on Visual Pigment Structure

a. Changes in Opsin Configuration on Bleaching Rhodopsin

b. Irradiation of Prelumi-, Lumi- and Metarhodopsin

c. Structural Alterations Associated with the Formation of Prelumi-, Lumi- and Metarhodopsin

d. Changes in Opsin Configuration During the Breakdown of Metarhodopsin

e. Apparent Heterogeneity of Prelumi-, Lumi- and Metarhodopsin

f . Structures of Squid and Cattle Metarhodopsin and their Bearing on the Structure of Visual-Pigment Chromophores

11. Reactions in the Retina

12. The Mechanism of Visual Excitation

Acknowledgement

References

Chapter III. Bioluminescence

1. Introduction

2. Synopsis of Extracted Systems

3. The Specific Systems in Vitro

a. The Jellyfish, Aequorea and Halistaura (Hydrozoan Coelenterates)

b. Cypridina (Ostracod Crustacean)

c. Pholas Dactylus (Pelecypod Mollusc)

d. Latia Neritoides (Gastropod Mollusc)

e. Hoplophorus Gracilorostris (Decapod Shrimp)

f. Meganyctiphanes; Thysonoessa (Euphausid Shrimp)

g. Odontosyllis (Polychaete Annelid)

h. Gonyaulax (Dinoflagellate Protozoan)

i. Balattoglossiis (Marine Hemichordate)

j. Earthworms (Oligochaete Annelids)

k. Chaetopteriis (Polychaete Annelid Worm)

l. Luminous Bacteria

m. Luminous Fungi (Basidiomycetes)

n. The Firefly System

o. The Sea Pansy, Renilla (Anthozoan Pennatulacean Coelenterate)

p. Arachnocampa (Bolitophila) Luminosa, the Dipterous "New Zealand Glowworm"

References

Chapter IV. Photosensitization

1. Introduction

2. The Oxidation of Proteins

3. Inactivation of Viruses

4. Nucleic Acids

5. Furocoumarins and Polycyclic Hydrocarbons

6. Mechanisms of the Reaction

a. Reactions with Oxygen

b. Direct Reaction with Substrate

Acknowledgements

References

Chapter V. The Effects of Ultraviolet Radiation and Photoreactivation

1. Introduction

2. General Principles and Methods

a. Absorption

b. Quantum Yield

c. Intensity

d. Monochromatic Radiation

e. Experimental Variables

f. Reciprocity

g. Action Spectra

h. Dose-Effect Curves

3. Proteins and their Components

a. Amino Acids

b. Enzyme Inactivation and Amino Acid Damage

c. Quantum Yields for Enzyme Inactivation

d. Energy Transfer

e. Gross Changes

4. Nucleic Acids and their Components

a. Energy Transfer

b. Action Spectra

c. Biologically Important Changes in DNA

d. Chain Breaks

e. DNA-DNA Cross-Links

f. Protein-DNA Cross-Links

g. Purines and Pyrimidines

h. Hydrates

i. Pyrimidine Dimers

5. Photoreactivation

a. Occurrence

b. In Vitro Photoreactivation

c. The Chemical Nature of Photoreactivable Damage

d. Nonphotoreactivable Damage

6. Dark Repair

a. Excision in Escherichia Coli

b. Excision of Damage Other than UV Damage

c. Excision in Other Systems

d. Repair Replication

7. Summary

Acknowledgements

References

Chapter VI. Phytochrome and Photoperiodism in Plants

1. Introduction

2. Dependence of Plant Photomorphogenesis on Night Length

3. Reversibility of Potentiated Flowering Response

4. Action Spectra for Non-Periodic Responses

5. Molecular Deductions from Physiological Responses

6. Spectrophotometric Assay

7. Isolation of Phytochrome

8. Properties of Phytochrome

9. Nature of the Chromophore

10. Flash Spectrophotometry

11. Chemical Evidence of Phytochrome Action

12. Metabolic Control and Rhythmic Change

References

Chapter VII. Photosynthesis

1. Introduction and Methods

2. Photosynthetic Pigments

3. Pigment Systems and Light Reactions

4. Primary and Related Processes

a. The Primary Reactions in Purple Bacteria

b. The Primary Reactions in Algae and Higher Plants

c. Primary Reaction 2

d. The Photosynthetic Unit and the Possibility of Energy Transfer Between Units

e. Energy Transfer Between System 1 and 2

5. Dark Reactions

a. Reduced Products of Photoreaction 1, the Photoreduction of NADP

b. Plastoquinones and Cytochrome b6

c. Oxygen Evolution

d. Photosynthetic Phosphorylation

e. Hill Reaction

f. Separation of the Two Pigment Systems

6. Conclusions

References

Chapter VIII. Effects of Ionizing Radiations on Biological Macromolecules

1. Introduction

a. Interaction of Ionizing Radiations with Matter

b. Direct and Indirect Action

c. The Role of Metabolism

2. Proteins

a. Introduction

b. Direct Action

c. Indirect Action

3. Polysaccharides

4. Nucleic Acids

a. Introduction

b. Damage to Nucleic Acid Constituents

c. Damage to Nucleic Acids

5. Nucleoproteins, Viruses and Cells

a. Isolated Nucleoproteins

b. Viruses

c. Bacterial and Mammalian Cells

d. Radiosensitization and Protection at the DNA Level

6. Ribonucleic Acids and Nucleoproteins

References

Subject Index