Answer
The correct answer is $d. enterokinase.$
Work Step by Step
The correct answer is $d. enterokinase$.
Enterokinase is an enzyme found in the small intestine, specifically in the duodenum. It plays a crucial role in digestion by activating trypsinogen, an inactive precursor enzyme produced by the pancreas, into its active form called trypsin. Trypsin then goes on to activate other pancreatic enzymes involved in the digestion of proteins.
While enterokinase itself is not directly involved in digesting nutrients, it has a significant role in initiating the digestion process by activating trypsinogen. The other enzymes mentioned in the options are involved in various stages of nutrient digestion:
a. Chymotrypsin - Digests proteins in the small intestine.
b. Lingual Lipase - Digests lipids (fats) in the stomach.
c. Carboxypeptidase - Acts in the small intestine to remove amino acids from the carboxyl end of peptides.
e. Dextrinase - Digests carbohydrates (specifically dextrins) in the small intestine.
So, among the options provided, $enterokinase$ is the enzyme that doesn't directly digest nutrients; rather, it initiates the digestion process by activating trypsinogen.
