/l/ Native, denatured, or coagulated. /2/ Secreted by the gastric mucosa as pepsinogen; activated by TCI. 

 Pepsin is an autocatalytic endopeptldase, hydrolyzing peptide bonds in the interior of the protein molecule. 

 /5/ In gastric juice of the young of some mammals, but probably not the adults; converts soluble calcium 

 caseinate to insoluble calcium paracaselnate (clot), /k/ Secreted in pancreatic Juice as trypsinogen; acti- 

 vated by enterokinase . Trypsin is an autocatalytic endopeptldase, hydrolyzlng native proteins to proteoses, 

 peptones, and polypeptides by splitting peptide bonds involving a basic nitrogen (as in lysine, arginine). 

 /5/ Secreted in pancreatic Juice as chymotrypsinogen; activated by trypsin. Chymotrypsin is an endopeptldase, 

 hydrolyzlng native proteins to proteoses, peptones, and polypeptides by splitting peptide bonds involving an 

 aromatic group (as in tyrosine, phenylalanine). /6/ Secondary protein derivatives of molecular weight less 

 than 1000, exclusive of polypeptides and simpler degradation products. /7/ Some absorption. /8/ A compound 

 containing more than two amino acids Joined by peptide linkages. /9/ One of several exopeptldases (called 

 erepsln) in pancreatice Juice removing successively amino acids with free carboxyl groups from the end of the 

 peptide chain, thus hydrolyzlng polypeptides to sin5>ler peptides and amino acids. /lO/ Secreted by intesti- 

 ■al mucosa in succus entericus; an exopeptldase, removing successively amino acids with free amino groups 

 from the end of the peptide chain, thus hydrolyzlng polypeptides to sin^iler peptides and amino acids, /ll/ 

 Dlpeptides contain two amino acids. /l2/ Secreted by intestinal mucosa in succus entericus; hydrolyzes dl- 

 I)eptldes to amino acids by breaking the peptide linkage. /13/ Absorbed. 



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