B7.2 - 3 Digestion Flashcards
Ingestion
Taking of substances e.g food and drink into the body
Digestion
The breakdown of food
Absorption
The movement of nutrients from the intestines into the blood
Assimilation
Uptake and use of nutrients by cells
Egestion
The removal of undigested food from the body as faeces
Physical digestion
The breakdown of food into smaller pieces without chemical change to the food molecules, it increases surface area for the action of enzymes in chemical digestion
Chemical digestion
The breakdown of large insoluble molecules into small soluble molecules, this is done so that the small soluble molecules can be absorbed
What is the function of amylase
To break down starch into simple reducing sugars
What is the function of proteases
To break down protein into amino acids
What is the function of lipase
To break down fats and oils into fatty acids and glycerol
Where is amylase secreted and where does it act
Secreted by pancreas (acts in) into duodenum
Where is protease secreted and where does it act
Pepsin - stomach
Trypsin - secreted by pancreas and acts in the duodenum (small intestine)
Where is lipase secreted and where does it act
In the mouth, pancreas (leading to it acting the duodenum) and stomach
What is the function of hydrochloride acid in gastric juice
Killing harmful microorganisms in food and providing an acidic pH for optimum enzyme activity of proteases in the stomach
What is the purpose of bile
It is an alkaline mixture that neutralises the acidic mixture of food and gastric juices entering the duodenum from the stomach, to provide a suitable pH for enzyme action in the small intestine
