The Energy of the Living Protoplasm. 



BY 



Dr. Oscar Loew. Professor of Agricultural Chemistry. 



Chapter VI. 

 The Chemical Activity of Living Cells. 



The great chemical activity of living cells astonishes the 

 pondering mind. The synthesis of carbohydrates, the transforma- 

 tion of starch into cellulose and fat, the production of the highly 

 complicated proteids are executed with admirable readiness by 

 plant-cells. Animal protoplasm also — although in extent and 

 power of chemical synthesis far excelled by vegetal protoplasm — 

 is capable of many highly interesting chemical operations, such 

 as the construction of living protoplasm out of inert albuminous 

 matter, the formation of haemoglobin, mucin, elastin, keratin, 

 and glutin from the proteids of the food, the production of 

 enzymes, or the transformation of sugar into fat. And not less 

 remarkable than the synthetical work is the energetic oxidation 

 exhibited by the respiration process.' 1 ' 



The character of the chemical work in plant-cells is many- 

 sided : polymerisation, condensation, esterification, formation of 

 amido-compounds, generation of the cyclic constitution, reduc- 

 tions and oxidations are included in it. We find acids and 

 bases, aldehydes and ketones, esters, alcohols, and sulphides in 

 the vegetal kingdom; but neither aldoximes, nor ketoximes, ( 2) 

 neither sulpho-acids, nor nitro-, nor azo-compounds. Thus, the 

 chemical activity, varied as it is, seems, nevertheless, not to 

 leave certain channels. (3) A number of chemical operations 



(1) See the following chapter. 



(2) No derivative of hydroxylamine has as yet been discovered in plant-cells. 



(3) It is a notable fact, for which hitherto explanation has not been given, that 

 especially such benzene derivatives as have a lateral chain of three carbon atoms 

 frequently occur in plants, some in form of glucosides. I will mention : hesperidic 

 acid, caffeic acid, melilotic acid, cumarin, umbelliferone, daphnetin, coniferyl alco- 

 hol, eugenol, anethol, safrol, cinnamic alcohol and aldehyde, cinnamic acid, thymol, 

 scopoletin, asarone, syringin, sesculetin, absinthol, camphor, the terpenes. Also, 

 tyrosin and phenylamidopropionic acid, as decomposition-products of proteids, have 

 to be mentioned (See Ch. V). 



