INORGANIC COMPOUNDS 25 



Compound Albuminoids: Hemoglobin in red cells of 



blood (coloring matter). 

 Mucin in secretions of mucous membranes and 



epithelial cells. 



Nuclein in the nuclei of tissue cells and sub- 

 stance (rich in phosphorus). 



Proteoses and Peptones. These are resulting proteins 

 formed during digestion by the action of the gastric 

 and pancreatic juices upon the proteins as they pass 

 through the process of digestion in the stomach and 

 intestines. 



Three coagulated proteins are formed when soluble 

 proteins are acted upon by animal ferments, e. g., 

 fibrin, myosin, casein. 



Fibrin. This is formed from the soluble protein 

 fibrinogen by the action of a special ferment. It is 

 not found except when blood is withdrawn from the 

 vessels or when coagulation occurs. Blood-clots fol- 

 lowing hemorrhage, by the action of the ferment on 

 the fibrinogen, forming fibrin. 



Myosin. This is a protein derived from a soluble 

 protein myosinogen. It occurs in muscles after death 

 and accounts for the stiffness of the limbs rigor 

 mortis. 



Casein. This is formed as a result of the action of 

 a special ferment rennin, a constituent of the gastric 

 juice acting upon the protein caseinogen of milk. 

 This is the ferment which splits milk into curds and 

 whey or junket. The curds represent the solid por- 

 tion or casein; the whey, the liquid portion. (See 

 Digestion.) 



INORGANIC COMPOUNDS 



Water (H 2 O). Water is the most important inor- 

 ganic substance essential to life. It is in the tissues 

 and fluids of the body, comprising 75 to 90 per cent, 

 of its weight. In a person weighing 165 pounds, 115 



