xii CONTENTS 



PAGE 



SECTION VIIL PROTEINS 3i 



General properties 3 2 



Microchemical reactions 38 



Proteins as colloids 38 



Decomposition products .... 

 Amino acids obtained as cleavage products of proteins 



Constitution of the protein molecule 



Polypeptides ....... 



Occurrence of amino acids in plants 



Classification of proteins 



Comparison between vegetable and animal proteins .... 



Extraction oi proteins . 



Synthesis of proteins in the plant 



Synthesis of amino acids in the plant 



Estimation of nitrogen 



SECTION IX. ENZYMES 344 



Classification 34^ 



Isolation 349 



Chemical constitution 349 



Properties 350 



Colloidal nature of enzymes 351 



Mode of action 352 



Activators 354 



Paralysers 356 



Anti-enzymes 358 



Enzymes and the laws of mass action ....... 361 



Consideration of certain types of enzymes ...... 365 



Lipase 366 



Isolation 367 



Quantitative determination of activity 368 



Diastase 368 



Isolation 369 



Quantitative determination of activity . . . ... 370 



Proteases 370 



Isolation 370 



General considerations 372 



Tryptophane reaction ........ 373 



Quantitative determination of activity ..... 374 



Zymase and alcoholic fermentation 374 



Isolation of zymase ...... . 377 



General considerations 377 



Identification of ethyl alcohol ...... 382 



Quantitative determination of activity 383 



Occurrence of alcohols in plants 385 



Inosite 387 



Manufacture of ethyl alcohol 389 



Oxidases 390 



Isolation 3Q2 



Peroxidase 



392 



INDEX 



Preparation ......... 393 



Identification ......... 393 



General considerations ........ 



399 



