Final answer:
The conversion of chymotrypsinogen to chymotrypsin in the small intestine is an example of zymogen activation, which is a crucial step for proper protein digestion.
Step-by-step explanation:
The conversion of inactive chymotrypsinogen to active chymotrypsin, a digestive enzyme, is an example of the activation of a zymogen or proenzyme. This biochemical process takes place in the small intestine where pancreatic enzymes are secreted in their inactive forms to prevent the digestion of the pancreas itself. The enzymes like chymotrypsin are stored as chymotrypsinogen in the pancreas and converted to their active forms in the intestine where they catalyze the hydrolysis of peptide bonds, particularly those involving aromatic amino acids such as phenylalanine, tyrosine, and tryptophan.
Enzymes in their inactive forms are known as proenzymes or zymogens. Upon release into the small intestine, enterokinase (also referred to as enteropeptidase) converts trypsinogen into trypsin. Subsequently, trypsin activates chymotrypsinogen to chymotrypsin through a process known as proteolysis. This cascade is a protective mechanism to avoid self-digestion, ensuring that the enzyme activity is confined to the small intestine where protein digestion is completed. Activated chymotrypsin then participates in breaking down proteins by attacking the peptide bonds associated with aromatic amino acids.