Question

Which of the following is a substrate of trypsin?
A. Protein
B. Fat
C. Carbohydrate
D. Amino acid

Answer 1

A substrate is a type of chemical species or molecule that is acted upon by enzymes. The substrate binds with the active site of the enzyme and then the product is formed. The substrate is also referred to as a surface over which other chemical reactions take place. Trypsin is a macromolecule made up of amino acids.

Complete answer: The small intestine has three main parts. These three parts are the duodenum, jejunum, and ileum. The duodenum is the twenty-five to thirty centimetres long, C-shaped part of the small intestine. Two different kinds of juices work in the duodenum to facilitate and carry out the process of digestion. These juices are the bile juice and the pancreatic juice. The pancreatic juice is secreted from the pancreas. It is secreted from the pancreatic duct also known as the Wirsung duct. The pancreatic juice is considered a complete juice because it contains all types of enzymes that are required for the digestion of various components of food. One such enzyme of the pancreas is trypsin. The inactivated form of trypsin is trypsinogen. The trypsin enzyme acts on proteins that convert polypeptides and peptones into dipeptides. The inactive trypsinogen is converted to the active trypsin by the enterokinase enzyme from the ileum.
Hence, the correct answer is option A.

Note: Apart from trypsin, there are other enzymes involved in the digestion of proteins that are present in the pancreatic juice. These enzymes are chymotrypsin that digests milk proteins, elastase that digests fibrous proteins, carboxypeptidase that digests other proteins, etc.