Enzymes like pepsin are created in the form of pepsinogen, an inactive zymogen.
From the en.wikipedia.org
Pepsinogen is activated when Chief cells release it into HCl which partially activates it.
From the en.wikipedia.org
Another partially activated pepsinogen completes the activation by removing the peptide turning the pepsinogen into pepsin.
From the en.wikipedia.org
The impressively named chief cells secrete pepsinogen which, when it mixes with stomach acid, becomes an enzyme called pepsin.
From the guardian.co.uk
Digestion typically begins in the stomach when pepsinogen is converted to pepsin by the action of hydrochloric acid, and continued by trypsin and chymotrypsin in the intestine.
From the en.wikipedia.org
The epithelium and lamina are filled with connective tissue and covered in gastric glands that may be simple or branched tubular, and secrete mucus, hydrochloric acid, pepsinogen and rennin.
From the en.wikipedia.org
More examples
Precursor of pepsin; stored in the stomach walls and converted to pepsin by hydrochloric acid in the stomach
Pepsin is an enzyme whose precursor form (pepsinogen) is released by the chief cells in the stomach and that degrades food proteins into peptides. It was discovered in 1836 by Theodor Schwann who also coined its name from the Greek word pepsis, meaning digestion (peptein: to digest). ...
An inactive form of pepsin; synthesized and stored in cells lining the gastric pits of the stomach.
Inactive precursor of pepsin, secreted into the gastric lumen.
Inactive proenzyme converted to the active protein-splitting enzyme (pepsin) by the action of hydrochloric acid
Inactive chemical found inside the stomach glands which keeps the stomach glands (which are made of protein) from digesting themselves