Enzymes, such as human pepsin, are biological catalysts. This means they are chemicals that speed up reactions in the body and consequently, are not consumed in the reaction. Specifically, human pepsin helps digest proteins. Dr. Laura lee Sherwood in her book “Human Physiology “explains that is secreted by specialized cells in the stomach lining cells called main. Indeed the human pepsin is a protein having biological activity in the stomach. It is secreted by the cells lining the stomach and then it is released as pepsinogen.

Human Pepsin was discovered in 1836 by Theodor Schwann, German physiologist considered the founder of modern histology which is the study of the structure of animal and plant tissues. It was not crystallized until 1929, from that date the crystallization process was conducted by scientist John Northrop using the basics of biotechnology.

After this incredible process that happens every day inside the human body was unveiled by the scientists, they realize that human pepsin breaks down proteins into smaller portions (polypeptides) and amino acids without degrading it completely, this is the same function that is performed by other enzymes in the intestine and requires a low pH or acidic pH to operate. The appropriate pH ranges between 1.5 and 2.5. Amino acids by pepsin released are phenylalanine, tryptophan and tyrosine mainly.

The function of hydrochloric acid inside the stomach is denature proteins; activate pepsinogen change to pepsin and start the hydrolysis process of proteins. Pepsinogen is the inactive form of human pepsin. Pepsin preferentially hydrolyzes peptide bonds, amino group belongs to the aromatic amino acids, but makes the process slow hydrolyzing other links.