Search results
Results from the WOW.Com Content Network
Pepsin / ˈ p ɛ p s ɪ n / is an endopeptidase that breaks down proteins into smaller peptides and amino acids.It is one of the main digestive enzymes in the digestive systems of humans and many other animals, where it helps digest the proteins in food.
It is produced in the stomach by gastric chief cells in its inactive form pepsinogen, which is a zymogen. Pepsinogen is then activated by the stomach acid into its active form, pepsin. Pepsin breaks down the protein in the food into smaller particles, such as peptide fragments and amino acids.
The parietal cell releases bicarbonate into the bloodstream in the process, which causes a temporary rise of pH in the blood, known as an alkaline tide. The acidic gastric juice also contains digestive enzymes produced by other cells in the gastric glands – gastric chief cells. Gastric chief cells secrete an inactivated pepsinogen.
The endocrine part secretes insulin when the blood sugar becomes high; insulin moves glucose from the blood into the muscles and other tissues for use as energy. The endocrine part releases glucagon when the blood sugar is low; glucagon allows stored sugar to be broken down into glucose by the liver in order to re-balance the sugar levels.
Glucose (blood sugar) is distributed to cells in the tissues, where it is broken down via cellular respiration, or stored as glycogen. [ 3 ] [ 4 ] In cellular (aerobic) respiration, glucose and oxygen are metabolized to release energy, with carbon dioxide and water as endproducts.
In glycolysis, a six-carbon glucose molecule is split into two three-carbon molecules called pyruvate. These carbon molecules are oxidized into NADH and ATP. For the glucose molecule to oxidize into pyruvate, an input of ATP molecules is required. This is known as the investment phase, in which a total of two ATP molecules are consumed.
On its own, seltzer does not have minerals and is naturally sugar- and calorie-free. However, many seltzer water brands do have added flavorings or sweeteners, such as natural fruit essences ...
Water and minerals are reabsorbed back into the blood in the colon (large intestine) where the pH is slightly acidic (about 5.6 ~ 6.9). Some vitamins, such as biotin and vitamin K (K 2 MK7) produced by bacteria in the colon are also absorbed into the blood in the colon. Absorption of water, simple sugar and alcohol also takes place in stomach.