1 68 RESPIRATION 



peptides and peptones giving origin to ammonia, carbon di- 

 oxide, and an aldehyde 



R . CH . NH„ . COOH + O -> R . CHO + NH 3 + C0 2 . 



The process is accelerated by the presence of certain reagents 

 such as phosphoric acid. 



Pirschle * has shown that in the respiration of many 

 fat-containing seeds such as Helianthus, Linum, Cannabis, 

 Brassica, Raphanus, and Cucurbita there is produced, as in 

 the germination of carbohydrate and protein-containing seeds, 

 acetic aldehyde ; it is, however, not certain whether the acetic 

 aldehyde in this instance is a direct product of the respiration 

 of the fat, it may in part be an intermediate product in the 

 transformation of fat into sugar previous to the respiratory 

 consumption of the resulting sugar. 



The foregoing account is almost entirely confined to the 

 activities of higher plants. The lower plants, more especially 

 the bacteria, obtain their respiratory energy in diverse ways 

 as is indicated by their physiological classification into sul- 

 phur, iron and nitrifying bacteria. For information on this, 

 text-books on bacteriology must be consulted. 



* Pirschle : " Biochem. Zeit.," 1926, 169, 482. 



