Chemical digestion Flashcards
Amylase
Breaks down starch to maltose
In what two parts of the alimentary canal are amylase secreted?
In the mouth- contained in saliva
In the small intestine (duodenum) - contained in pancreatic juice
Juice secreted in the stomach?
Gastric juice
What is contained in the juice secreted in the stomach?
Pepsin and hydrochloric acid
Pepsin
Breaks down proteins to polypeptides
Hydrochloric acid
Has a low pH to provide an optimum pH for pepsin activity and to denature enzymes in harmful microorganisms in food
What two juices are secreted into the duodenum?
Pancreatic juice and bile
Where is bile made and stored?
Made by liver, stored by gall bladder
What enzymes are contained in pancreatic juice?
Amylase, trypsin and lipase
Trypsin
Breaks down proteins to polypeptides
Lipase
Breaks down fats to fatty acids and glycerol
What else, other than enzymes, is contained in pancreatic juice?
sodium hydrogencarbonate (reduces acidity of chyme)
Function of bile in neutralisation
It neutralises the acidic mixture of food and gastric juices entering the duodenum from the stomach. This provides a suitable pH for enzyme action
How does bile help to digest fats?
It emulsifies fats to increase the surface area for the chemical digestion of fats to fatty acids and glycerol by lipase
Maltase
Breaks down maltose to glucose on the membranes of the epithelium lining the small intestine
