Digestion

Name:
Digestion
Detailed information:
(1) The physiological processes involved in the assimilation of nutrients from ingested foods by the animal organism. Hydrochloric acid in the gastric juice plays a prominent part, aided by the saliva which initiates carbohydrate breakdown, and bile and pancreatic secretions in the intestine. Numerous types of enzymes catalyze these processes. (2) In chemical engineering, the term refers to several processes: (a) the preferential dissolution of certain mineral constituents in some ore concentrates, (b) the liquefaction of organic waste materials by microbiological action as in activated sludge, (c) the removal of lignin from wood by hot chemical solutions in the manufacture of chemical cellulose and paper pulp, (d) the separation of fabric from scrap tires by hot sodium hydroxide solution in the reclaiming of rubber. The equipment for (c) and (d) is called a digester.See Metabolism; Nutrition.