The Chemical. Basis of Life 17 



Kephalin 



R"CO 

 O O 



NH 2 - CH 2 — CH 2 — O— P— O— CH 2 — CH— CH 2 



o o 



H R'CO 



Approximate Percentage Yield of Amino Acids from Proteins 



Egg Ca- Edes- Fi- Gela- Glia- Hemo- 

 Albumin sein tin brin tin din globin 



Glycine 0.0 0.5 3.8 3.0 



Alanine 8.1 1.5 3.6 3.6 



Valine 2.5 7.0 6.2 1.0 



Isoleucine 1.4 



11.0 21.0 15.0 7.1 5.6 30.0 



Leucine 7.9 



Phenylalanine... 5.1 3.9 3.1 2.5 



Tyrosine 1.8 5.0 2.1 3.5 



Aspartic acid 2.2 1.4 4.5 2.0 



Glutamic acid... 9.1 15.8 19.0 10.0 



Arginine 4.9 4.5 15.0 4.7 



Lysine 3.8 6.0 2.0 11.0 



Serine 0.0 0.4 0.3 0.8 



Cystine 0.3 0.02 1.0 1.2 



Proline 3.6 7.0 4.1 3.6 



Hydroxyproline 0.2 2.0 



Histidine 1.2 3.0 2.0 6.4 



Tryptophane + 1.5 0.4 1.3 + + 



The accompanying table gives the percentage 

 yields of the various amino acids from certain 

 proteins, but these values should be interpreted 



