Search results
Results From The WOW.Com Content Network
Human parietal cells (pink staining) – stomach. As a result of the cellular export of hydrogen ions, the gastric lumen is maintained as a highly acidic environment. The acidity aids in digestion of food by promoting the unfolding (or denaturing) of ingested proteins. As proteins unfold, the peptide bonds linking component amino acids are exposed.
The mucus produced by these cells is extremely important, as it prevents the stomach from digesting itself. [5] Parietal cells produce potent hydrochloric acid, which damages cells. Gastric chief cells produce pepsinogen, which is activated by the acid to form pepsin. Pepsin is a protease that can digest and damage stomach cells.
They are made of a bone-like material called dentin, which is covered by the hardest tissue in the body—enamel. [8] Teeth have different shapes to deal with different aspects of mastication employed in tearing and chewing pieces of food into smaller and smaller pieces. This results in a much larger surface area for the action of digestive ...
Gastric acid or stomach acid is the acidic component – hydrochloric acid of gastric juice, produced by parietal cells in the gastric glands of the stomach lining. In humans, the pH is between one and three, much lower than most other animals, but is very similar to that of carrion eating carnivores , needing protection from ingesting pathogens .
Digestive enzymes take part in the chemical process of digestion, which follows the mechanical process of digestion. Food consists of macromolecules of proteins, carbohydrates, and fats that need to be broken down chemically by digestive enzymes in the mouth , stomach , pancreas , and duodenum , before being able to be absorbed into the ...
The breakdown of protein begins in the stomach through the actions of hydrochloric acid, and the enzyme pepsin. The stomach can also produce gastric lipase , which can help digesting fat. The contents of the stomach are completely emptied into the duodenum within two to four hours after the meal is eaten.
Pepsin is expressed as a zymogen called pepsinogen, whose primary structure has an additional 44 amino acids compared to the active enzyme. In the stomach, gastric chief cells release pepsinogen. This zymogen is activated by hydrochloric acid (HCl), which is released from parietal cells in the stomach lining.
The parietal cells secrete hydrochloric acid (gastric acid). This needs to be readily available for the stomach in a plentiful supply, and so from their positions in the walls, their secretory networks of fine channels called canaliculi can project and ingress into all the regions