Chief cell
Encyclopedia
In general, a chief cell (or a "zymogen
ic cell") is a cell which releases a precursor enzyme
. There are two types of chief cells which are most commonly referenced:
Zymogen
A zymogen is an inactive enzyme precursor. A zymogen requires a biochemical change for it to become an active enzyme. The biochemical change usually occurs in a lysosome where a specific part of the precursor enzyme is cleaved in order to activate it...
ic cell") is a cell which releases a precursor enzyme
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
. There are two types of chief cells which are most commonly referenced:
- A gastric chief cellGastric chief cellA gastric chief cell is a cell in the stomach that releases pepsinogen, gastric lipase and Chymosin...
(or "peptic cell") is a cell in the stomachStomachThe stomach is a muscular, hollow, dilated part of the alimentary canal which functions as an important organ of the digestive tract in some animals, including vertebrates, echinoderms, insects , and molluscs. It is involved in the second phase of digestion, following mastication .The stomach is...
that releases pepsinogen and rennin. Usually when the term "chief cell" or "zymogenic cell" is used without qualification, this is the type meant. This type of cell also secretes gastric lipase enzymes, which help digest triglycerides into free fatty acids and di- and mono-glycerides. - The parathyroid chief cellParathyroid chief cellParathyroid chief cells are cells in the parathyroid glands which produce parathyroid hormone....
is the primary cell of the parathyroid glandParathyroid glandThe parathyroid glands are small endocrine glands in the neck that produce parathyroid hormone. Humans usually have four parathyroid glands, which are usually located on the rear surface of the thyroid gland, or, in rare cases, within the thyroid gland itself or in the chest...
. It produces and secretes parathyroid hormoneParathyroid hormoneParathyroid hormone , parathormone or parathyrin, is secreted by the chief cells of the parathyroid glands as a polypeptide containing 84 amino acids...
.