CONTENTS Xlll 



Page 



Chap. 15. The Pigment System 399 



A. General Composition 399 



B. The Chlorophylls 402 



1. Chlorophylls a and b and their Ratio 402 



2. Protochlorophyll 404 



3. The Chlorophylls of the Algae 405 



4. Bacteriochlorophyll and Bacterioviridin 407 



5. Concentration of Chlorophyll in Leaves 407 



6. ChlorophyU Content of Algae 408 



7. Chlorophyll Concentration in Single Cells and Chloroplasts . ... 411 



C. The Carotenoids 412 



D. The Phycobihns 417 



E. Influence of External Factors 419 



1. The Adaptation Phenomena 419 



2. Phylogenetic Adaptation of the Pigment System 420 



3. Ontogenetic Adaptation of the Pigment System 424 



4. Influence of Different Factors on Pigment Formation 427 



Bibliography 432 



Chap. 16. Chlorophyll 438 



A. Molecular Structure 438 



1 . Historical Remarks 438 



2. Structural Formula 439 



3. Bacteriochlorophyll and Protochlorophyll 444 



4. Porphins, Chlorins, Phorbins, Phytins, and PhyUins 445 



5. Shape and Size of the Chlorophyll Molecule 448 



B. Chemical Properties 450 



1. Chlorophyll and Water 450 



2. Chlorophyll and Carbon Dioxide 451 



3. Oxidation and Reduction of Chlorophyll 456 



4. Ehmination of Magnesium and Phytol 467 



Bibliography 467 



Chap. 17. The Accessory Pigments 470 



A. The Carotenoids 470 



1. Chemical Structure 470 



2. Oxidation and Reduction 473 



3. Carotenoids, Lipides, and Proteins 475 



B. The Phycobihns 476 



C. Flavones and Anthocyanins , 479 



Bibliography 480 



Chap. 18. Photochemistry of Pigments in vitro 483 



A. The Primary Photochemical Process 483 



1 . Long-Lived Activated States 484 



2. Reversible Photochemical Reactions 486 



B. The Irreversible Photochemical Transformations of Chlorophyll. . . 494 



1. Bleaching of Chlorophyll 494 



2. Photoxidation as the Cause of Bleaching 498 



3. Effect of Solvents and Protective Substances on Bleaching .... 501 



