Pepsin

Pepsin is a digestive protease released by the chief cells in the stomach that functions to degrade food proteins.

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According to American Heritage Dictionary, pepsin derives from the Greek word pepsis, meaning digestion (peptein: to digest).

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Pepsin was discovered by Theodor Schwann in 1836. It was the first animal enzyme to be discovered.

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Pepsin is expressed as a pro-form zymogen, pepsinogen, whose primary structure has an additional 44 amino acids. Hydrochloric acid released by the parietal cells converts pepsinogen to pepsin by cleaving off the additional amino acids outside the secreting cell to avoid digestion of the cells of the stomach and pancreas (like all cells, their membranes contain protein).

Digestive: Digestive may refer to:...

Protease: Proteases (proteinases, peptidases or proteolytic enzymes) are enzymes which break peptide bonds of proteins. The process is called proteolytic cleavage. They use a molecule of water for this and are thus classified as hydrolases....

Chief cell: In general, a chief cell (or a "zymogenic cell") is a cell which releases a precursor enzyme. There are two types of chief cells which are most commonly referenced:...