Enzymes digestive, secretion

FIGURE 2-21 The pH optima of some enzymes. Pepsin is a digestive enzyme secreted into gastric juice trypsin, a digestive enzyme that acts in the small intestine alkaline phosphatase of bone tissue, a hydrolytic enzyme thought to aid in bone mineralization. 

Trypsin, chymotrypsin, and elastase are three of the most important protein-digesting enzymes secreted by the pancreas. Despite their similarities they have different substrate specificity, that is, they cleave different peptide bonds during protein digestion. 

Lumenal metabolism. This may be triggered by digestive enzymes secreted from the pancreas (amylase, lipases, and peptidases including trypsin and a-chymotrypsin), and those derived... 

CAS 9001-98-3. A digestive enzyme secreted by the glands of the stomach and causes curdling of milk. It has the power of coagulating 25,000 times its own weight of milk. 

Chymotrypsin, trypsin, and elastin are digestive enzymes secreted by the pancreas into the small intestine to catalyze the hydrolysis of peptide bonds. These enzymes are all called serine proteases because the mechanism for their proteolytic activity (one that they have in common) involves a particular serine residue that is essential for their enzymatic activity. As another example of how enzymes work, we shall examine the mechanism of action of chymotrypsin. 

The rapid turnover of intestinal mucosal cells is also important for protection of the intestine against the digestive enzymes secreted into the lumen. Further protection is afforded by the secretion of mucus, a solution of proteins that are resistant to enzymic... 

A digestive enzyme, secreted by the pancreas, which hydrolyses peptide bonds formed from the carboxyl group of lysine or arginine. It is secreted into the duodenum as its inactive precursor, trypsinogen, and this is converted to trypsin by the action of the intestinal enzyme, enterokinase. The newly formed trypsin can also activate trypsinogen. 

A digestive enzyme secreted by the pancreas. It helps to break down (digest) starch to the sugar, maltose. Another name for this enzyme is pancreatic amylase. 

A digestive enzyme secreted by the pancreas via the pancreatic juice into the small intestine where it digests protein. (Also see DIGESTION AND ABSORPTION.)... 

A digestive enzyme secreted by the pancreas, which acts on proteins. 

Carriere, E, Grandval, P, Renou, C., Palomba, A., Prieri, E, Giallo, J., Henniges, E, Sander-Struckmeier, S., and Laugier, R. Quantitative study of digestive enzyme secretion and gastrointestinal lipolysis in chronic pancreatitis. Clin. Gastroenterol. Hepatol. 3, 28-38, 2005. 

Pancreatin is a commercial product containing significant amounts of the digestive enzymes secreted by the pancreas. It is used as a food supplement to complement inadequate pancreatic function. Figure 4 (p. 153) shows a chromatogram of a pancreatin extract, together with the results of assaying the fractions collected with a specific colorimetric substrate for trypsin-like enzymes. 

Some mammalian enzymes are present outside the limits of the cell plasma membrane. These include digestive enzymes secreted into the intestinal lumen, enzymes involved in blood clotting, and also enzymes which have "leaked" from cells. This last group includes most of the blood enzymes used as tissue-specific markers of cell damage. In this chapter I shall not discuss the breakdown of extracellular enzymes... 

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