每日医词343
【医词重点】
endopeptidase [endəʊ'peptɪdeɪs] n.肽链内切酶，内肽酶
exopeptidase [eksəʊ'peptɪdeɪs] n.肽链端解酶，外肽酶
【构词法】
前缀：endo-，内在的，在内的；
词根：peptidase，肽酶àn.endopeptidase 内肽酶
前缀：exo-,外在的，在外的；
词根：peptidase，肽酶àn. exopeptidase 外肽酶
【同根词】
polypeptidase [pɒlɪ'peptɪdeɪs]n.多肽酶
【同缀词】
endogenous [enˈdɒdʒənəs]adj.内长的，内生的
exothermic [ˌeksəʊˈθɜ:mɪk]adj.发热的，放出热量的
【应用举例】
A new endopeptidase isozyme with higher activity was detected by electrophoresis on polyacrylamide gels denatured hemoglobin.
Non - toxic inhibitor for esterase, lipase and N - formyl - methionine aminopeptidase. Inhibits also carboxypeptidase Y - like exopeptidase.
【医学英语课堂】
Digestive enzymes are enzymes that break down polymeric macromolecules into their smaller building blocks, in order to facilitate their absorption by the body.
Digestive enzymes are diverse and are found in the saliva secreted by the salivary glands, in the stomach secreted by cells lining the stomach, in the pancreatic juice secreted by pancreatic exocrine cells, and in the intestinal (small and large) secretions, or as part of the lining of the gastrointestinal tract.
①mechanical digestion
②chemical digestion.
【食物消化全过程】
In the human digestive system, food enters the mouth and mechanical digestion of the food starts by the action of mastication, a form of mechanical digestion, and the wetting contact of saliva.
Saliva, a liquid secreted by the salivary glands, contains salivary amylase, an enzyme which starts the digestion of starch in the food.
After undergoing mastication and starch digestion, the food will be in the form of a small, round slurry mass called a bolus.
It will then travel down the esophagus and into the stomach by the action of peristalsis.
Gastric juice in the stomach starts protein digestion. Gastric juice mainly contains hydrochloric acid and pepsin.
As these two chemicals may damage the stomach wall, mucus is secreted by the stomach, providing a slimy layer that acts as a shield against the damaging effects of the chemicals.
At the same time protein digestion is occurring, mechanical mixing occurs by peristalsis, which is waves of muscular contractions that move along the stomach wall. This allows the mass of food to further mix with the digestive enzymes.
After some time (typically 1–2 hours in humans, 4–6 hours in dogs, 3–4 hours in house cats), the resulting thick liquid is called chyme.
When the pyloric sphincter valve opens, chyme enters the duodenum where it mixes with digestive enzymes from the pancreas, and then passes through the small intestine, in which digestion continues.
When the chyme is fully digested, it is absorbed into the blood. 95% of absorption of nutrients occurs in the small intestine.
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 (K2MK7) produced by bacteria in the colon are also absorbed into the blood in the colon.
Waste material is eliminated from the rectum during defecation.
欢迎加入小和尚医学英语，群号码：426478104
【医词重点】
endopeptidase [endəʊ'peptɪdeɪs] n.肽链内切酶，内肽酶
exopeptidase [eksəʊ'peptɪdeɪs] n.肽链端解酶，外肽酶
【构词法】
前缀：endo-，内在的，在内的；
词根：peptidase，肽酶àn.endopeptidase 内肽酶
前缀：exo-,外在的，在外的；
词根：peptidase，肽酶àn. exopeptidase 外肽酶
【同根词】
polypeptidase [pɒlɪ'peptɪdeɪs]n.多肽酶
【同缀词】
endogenous [enˈdɒdʒənəs]adj.内长的，内生的
exothermic [ˌeksəʊˈθɜ:mɪk]adj.发热的，放出热量的
【应用举例】
A new endopeptidase isozyme with higher activity was detected by electrophoresis on polyacrylamide gels denatured hemoglobin.
Non - toxic inhibitor for esterase, lipase and N - formyl - methionine aminopeptidase. Inhibits also carboxypeptidase Y - like exopeptidase.
【医学英语课堂】
Digestive enzymes are enzymes that break down polymeric macromolecules into their smaller building blocks, in order to facilitate their absorption by the body.
Digestive enzymes are diverse and are found in the saliva secreted by the salivary glands, in the stomach secreted by cells lining the stomach, in the pancreatic juice secreted by pancreatic exocrine cells, and in the intestinal (small and large) secretions, or as part of the lining of the gastrointestinal tract.
①mechanical digestion
②chemical digestion.
【食物消化全过程】
In the human digestive system, food enters the mouth and mechanical digestion of the food starts by the action of mastication, a form of mechanical digestion, and the wetting contact of saliva.
Saliva, a liquid secreted by the salivary glands, contains salivary amylase, an enzyme which starts the digestion of starch in the food.
After undergoing mastication and starch digestion, the food will be in the form of a small, round slurry mass called a bolus.
It will then travel down the esophagus and into the stomach by the action of peristalsis.
Gastric juice in the stomach starts protein digestion. Gastric juice mainly contains hydrochloric acid and pepsin.
As these two chemicals may damage the stomach wall, mucus is secreted by the stomach, providing a slimy layer that acts as a shield against the damaging effects of the chemicals.
At the same time protein digestion is occurring, mechanical mixing occurs by peristalsis, which is waves of muscular contractions that move along the stomach wall. This allows the mass of food to further mix with the digestive enzymes.
After some time (typically 1–2 hours in humans, 4–6 hours in dogs, 3–4 hours in house cats), the resulting thick liquid is called chyme.
When the pyloric sphincter valve opens, chyme enters the duodenum where it mixes with digestive enzymes from the pancreas, and then passes through the small intestine, in which digestion continues.
When the chyme is fully digested, it is absorbed into the blood. 95% of absorption of nutrients occurs in the small intestine.
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 (K2MK7) produced by bacteria in the colon are also absorbed into the blood in the colon.
Waste material is eliminated from the rectum during defecation.
欢迎加入小和尚医学英语，群号码：426478104
