Enzyme refers to a kind of biocatalyst produced by living cells. It can efficiently catalyze plentiful biochemical reactions under very mild conditions, and promote the metabolism of the organism. There are at least more than 4,000 enzymes in our body. Breathing, Digestion, breathing, absorption, exercise and reproduction in life activities are all enzyme-promoting reactions.
Animals must absorb the nutrients they need through the digestive process by feeding food to provide energy for the growth and physiological processes. For the human beings, digestive system contains the digestive glands and digestive tract. The digestive tract of a normal male adult is approximately 6 meters long and consists of the upper and lower digestive tracts. The digestive tract is a tube that connects the mouth and anus and consists of many structures that handle food.
Although the amylase is called “amylase”, it actually breaks down “polysaccharides formed by glucose with α-1,4 glycosidic bonds as the main connection method” (may be referred to as “αglucan”) — -This includes not only amylose and amylopectin in plants (among which alpha-1,6 glycosidic bonds that amylase cannot hydrolyze), but also glycogen (structurally) in animal tissues (mainly muscle and liver) Similar to amylopectin in plants, but with a much smaller molecular weight)-or “animal starch”.
Clinical significance
Pancreatic amylase is excreted by the pancreas into the digestive tract in an active state. It is the most important enzyme that hydrolyzes carbohydrates. Like the amylase secreted by the salivary glands, it belongs to α-amylase, which acts on the α-1,4 glycosidic bond and acts on branches The α-1,6 glycosidic bond has no effect, so it is also called endo-amylase. Its optimum pH is 6.9, which can be filtered through the glomerulus. It is the only plasma enzyme that can occur in urine in normal times.
Amylase activity is found in extracts from other tissues of the human body such as the ovaries, fallopian tubes, lungs, testes, semen, breast, etc .; blood, urine, and milk also contain amylase. Blood amylase mainly comes from the pancreas and salivary glands, while urine amylase comes from the blood.
Amylase Activity in the Stomach
Physiological condition of stomach
Like most enzymes, amylases require certain conditions to exert their activity. In the oral cavity and pancreas, it requires an optimum pH of 6.7 to 7.0. It also works best at human temperatures and requires the presence of various other compounds. The condition in the stomach is completely different from the condition in the mouth. The presence of gastric acid makes the stomach strongly acidic, and the pH value during digestion is about 1.0 to 3.0. This is beyond the scope of what amylases can do.
Fundus activity
However, salivary amylase does not inactivate once it reaches the stomach. Since being secreted into the mouth, it continues to be active as food is swallowed and passes through the esophagus. From there, food enters the first part of the stomach, located on the upper curve, called the fundus. Food may stay here for about an hour without mixing with gastric fluid, during which amylase can continue to work.
Inactivation of amylase in the stomach
The fundus is mainly a storage area. Most of the activity occurs in the larger central part of the stomach, the human body. After food enters the stomach, a soft wave called peristalsis passes through the stomach. They mix and macerate the food to reduce it to chyme. Although these exercises do not affect the body as much as they do, the final agitation and mixing of chyme and gastric acid means that the amylase is inactivated.