X CONTENTS 



CHAPTER XII 



THE PLANT OXIDASES 



PAGES 



SECTION I. The nature of plant oxidases : Enzymic nature of oxidases 

 Effect of heat on oxidases Classification of oxidases Com- 

 ponent parts of a complete oxidase Composition and properties 

 of laccases or phenolases The influence of light upon the amount 

 of oxidase in plant tissues considered in relation to the composi- 

 tion of the enzyme Chemical composition of laccase Con\- 

 position and properties of tyrosinase Inhibitors or paralyzors 

 of oxidase action Separation of enzyme and inhibitor Mode 

 of action of inhibitors. SECTION II. Distribution of oxidases 

 in plant families : Plants with complete and incomplete peroxi- 

 dase systems Plants containing inhibitors Occurrence of 

 phenolases and tyrosinases Oxidase reagents and their limita- 

 tions. SECTION III. The quantitative estimation of oxidases : 

 Colorimetric methods for phenolases Volumetric methods for 

 phenolases Gravimetric method of Chodat and Bach Methods 

 for estimating tyrosine Manometric methods of measuring 

 oxidase activity Requirements and limitations of manometric 

 methods of estimating oxygen Bunzel's oxidase apparatus 

 Materials used in Bunzel's oxidase estimations The method of 

 carrying out estimations with Bunzel's apparatus The effect of 

 variable factors on the total oxygen absorption Typical estima- 

 tion by Bunzel's method 216250 



CHAPTER XIII 



THE OXIDASES IN RELATION TO PIGMENTATION, AND 

 THE AN.THOCYAN PIGMENTS 



SECTION I. Wheldale's theory of anthocyanin formation: Micro- 

 chemical and genetic researches on oxidase distribution The 

 oxidases of Cytisus Adami The restoration of anthocyan 

 pigment in decolorized petals Peroxidase reactions of related 

 species of Iris Effect of absence of light upon the peroxidase of 

 Iris flowers. SECTION II. The anthocyan pigments : Antho- 

 cyanin and its parent substances Mendelian experiments 

 bearing on anthocyanin formation Some sources and properties 

 of pure anthocyanins The artificial production of coloured 

 substances supposed to be anthocyanins Factors influencing 

 the production of anthocyan pigments The origin and dis- 

 tribution of anthocyanins in the cell Review of theories of 

 anthocyanin formation Provisional classification of plant 

 pigments 251292 



