THE PRODUCTS OF METABOLISM 



lOI 



Sterols appear to be totally lacking in the Myxophyceae 



53 



NITROGENOUS SUBSTANCES 



Little is known of the proteins of algae and as yet only 

 amino-acid analyses of the bulk proteins of certain species 

 are available.^^O' i^^' ^'^^ ^«' ^^' ^^^ The analytical results pre- 

 sented in Table 8 are not all of equal value. In Ulva, 

 Laminaria, Chondrus, Microcystis and Phormidium, not all 

 the protein nitrogen is accounted for and the protein frac- 

 tions examined may not have been representative of the 

 whole. It is thus possible that the amino-acids reported 

 as absent in these algae were, in fact, present and in this 



TABLE 8 



THE AMINO-ACID COMPOSITIONS OF THE BULK PROTEINS OF 

 VARIOUS ALGAE COMPARED WITH SIMILAR DATA FOR HIGHER PLANTS 



Amounts are given as g. amino-acid N/ioo g. protein N 



