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Title: pepsin released into the stomach to digest protein.since stomach wall is protein why it cant be digested too? Post by: irina on Sep 8, 2012 pepsin is an enzyme released into the stomach to digest protein. since stomach wall is made of protein, why is it not digested too?
Title: pepsin released into the stomach to digest protein.since stomach wall is protein why it cant be digested too? Post by: Lexington on Sep 8, 2012 The stomach is lined with a protective mucus as a barrier to pepsin. As it's being excreted and before it meets the stomach mucus, it's in the inactive form pepsinogen, which is activated where the mucus is, in the low pH stomach lumen
From http://library.thinkquest.org/22016/digestion/index.html "Pepsin is secreted in an inactive state, Pepsinogen, this is so that it doesn?t begin destroying the gastric gland(autodigestion). When it reaches the lumen it is activated by the hydrochloric acid. Cells in the wall secrete a mucus, which prevents it from eating away at the wall." Title: pepsin released into the stomach to digest protein.since stomach wall is protein why it cant be digested too? Post by: buddhadog on Sep 8, 2012 its protected by mucas
Title: pepsin released into the stomach to digest protein.since stomach wall is protein why it cant be digested too? Post by: Smitty on Sep 8, 2012 Yep, its mucus alright. Gotta love a stomach full of boogers! No it really is mucus though.
Title: pepsin released into the stomach to digest protein.since stomach wall is protein why it cant be digested too? Post by: lexus3431 on Sep 8, 2012 There are a lot of glands in the stomach; some of them release enzymes for proteines, some release enzymes for other macromolecules. But many glands release mucus for the protection of the gastric tissue and it is very effective.
If it is possible to you, check the studies made by Gerald and Theresa Audesirk. Title: pepsin released into the stomach to digest protein.since stomach wall is protein why it cant be digested too? Post by: ilikepie1234 on Sep 8, 2012 Because it has a special lining that prevents this from happening.
Title: pepsin released into the stomach to digest protein.since stomach wall is protein why it cant be digested too? Post by: buddhadog on Sep 8, 2012 Gastric secretions include pepsinogen, gastric lipase, hydrochloric acid, intrinsic factor,mucus and gastrin. The cells that secrete some of these products, called gland cells are specifically known as chief cells, parietal cells and mucous neck cells. Chief cells secrete pepsinogen, the precursor to the proteolytic enzyme pepsin, and gastric lipase, which breaks down short chain triglycerides. Pepsin is secreted in an inactive form so that it does not digest
proteins in the actual chief cells that secrete it; this enzyme is activated when it comes into contact with hydrochloric acid or other pepsin molecules. Parietal cells secrete hydrochloric acid via proton pumps and chloride leakage channels on their apical membranes. Apart from activating pepsinogen, this acid also kills microbes and denatures proteins. Mucous neck cells and surface cells secrete mucus, which forms a protective barrier that prevents the stomach wall from being digested by the stomach?s powerful enzymes. Gastrin is secreted by G cells, which are endocrine cells. |