Question

What is common among amylase, rennin and trypsin?
A) These are produced in stomach
B) These act at a pH lower than 7
C) These are all proteins
D) These all are proteolytic enzymes

Answer 1

Hint: Enzymes that take part in the process of digestion are mostly made up of proteins..

Complete solution:
Before we figure out what is common among the given set of proteins, let us first get to know each of these enzymes mentioned in the question.
Firstly, the amylase is the carbohydrates digesting enzyme. There are different types of amylases that work in different regions of the digestive tract, such as salivary amylase in the buccal cavity, pancreatic amylase in the small intestine. It is a proteinaceous enzyme. It simply means that it’s structure is proteinaceous.
Then we have rennin. Well, rennin is present only in infants, because their main diet is milk. Rennin is specific in digesting the milk proteins, so it is a proteolytic enzyme. But it is even made up of protein, so it is also a proteinaceous enzyme structurally.
Finally we are provided with trypsin, which is made in pancreas in an inactive form called trypsinogen and is activated in the small intestine. After activation, it performs the protein digestion, so it is a proteolytic enzyme. However, the structure of trypsin is yet again made up of protein.
So, we now understood that all of these enzymes, namely amylase, rennin and trypsin are proteinaceous enzymes.

Therefore, the correct answer is option c.

Note: Almost all enzymes are proteins, made up of chains of amino acids, and they perform the critical task of lowering the activation energies of chemical reactions inside the cell. However, we do have some RNA enzymes called the ribozymes.