Question

At what pH does pepsin work best?

Answer 1

Hint: In order to answer this question, first we will write the pH value where pepsin works best. And then we will discuss the reason behind it and we will also discuss much more about the pepsin and its properties.

Complete answer:
Pepsin is a proteolytic enzyme released as a proenzyme pepsinogen by the main cells of the gastric glands. Gastric $HCl$ acts as an activator. Pepsin's optimum pH is $1.8$ , which is quite acidic.
Because the carboxylic acid group on the amino acid in the enzyme's active site must be in its protonated state, meaning bonded to a hydrogen atom, pepsin works best at pH $1.8$ . The carboxylic acid group is protonated at low pH, allowing it to catalyse the chemical reaction of chemical bond breakage.
Pepsin is an endopeptidase enzyme that breaks down proteins into peptides. It is one of the most important digestive enzymes in the digestive systems of humans and many other animals, where it aids in the digestion of proteins in food. It is produced in the gastric chief cells of the stomach lining and is one of the most important digestive enzymes in the digestive systems of humans and many other animals. Pepsin is an aspartic protease with an active site that contains a catalytic aspartate.
It is one of three major proteases found in the human digestive tract, along with chymotrypsin and trypsin. These enzymes work together to break down food proteins into their constituents, peptides and amino acids, which are easily absorbed by the small intestine.

Note:
Depending on the quantity and intensity of these interactions, the effect of such ions will differ from protein to protein. Pepsin is thought to have evolved a structure with interactions that are less vulnerable to high hydrogen ion concentrations, and so does not denature at low pH.