MCQ Detailed View

Enzymes are biological catalysts that speed up chemical reactions in the body, particularly during digestion, where they break down large food molecules into smaller, absorbable units. Common digestive enzymes include pepsin, trypsin, and chemotrypsin, all of which are protein-degrading enzymes found in the stomach and pancreas.

Secretin, on the other hand, is not an enzyme but a hormone. It is produced by the small intestine in response to acidic food (chyme) entering from the stomach. Secretin stimulates the pancreas to release bicarbonate-rich fluids, which neutralize stomach acid in the duodenum. It also regulates water and enzyme secretion in the digestive tract but does not directly catalyze the breakdown of nutrients.

Here is a quick look at the listed options:

1. 
   

   Chemotrypsin: A digestive enzyme secreted by the pancreas that breaks down proteins into smaller peptides.

   
   


2. 
   

   Secretin: A hormone that regulates pH in the small intestine but does not function as an enzyme.

   
   


3. 
   

   Pepsin: A major enzyme in the stomach that breaks down proteins into peptides.

   
   

Since secretin is a regulatory hormone, not a catalytic enzyme, it does not participate directly in the chemical breakdown of food. This makes secretin the correct answer to this question.

Enzymes play a key role in metabolism and nutrient absorption, whereas hormones like secretin act as messengers, instructing other organs to release enzymes or digestive juices. Understanding the difference between enzymes and hormones is essential in learning how the digestive system works efficiently.