B7.2+7.3 Flashcards
Ingestion
Taking in of substances into the body (food, drink)
Digestion
The breakdown of food
Absorption
The movement of nutrients from the intestine into the blood
Assimilation
Uptake and use of nutrients by cells
Egestion
The removal of undigested waste products from the body as faeces
Physical digestion
Breakdown of food without any chemical change to the molecules
- increases surface area for action of enzymes
Chemical Digestion
Breakdown of large insoluble molecules into small soluble molecules
- in order for the molecules to be absorbed
What is the function of the amylase
To break down starch into reducing sugars
What is the function of a protease
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 from? (2)
Pancreas (small intestine) + Salivary glands
Where does amylase act? (2)
Mouth, Duodenum
Where is Protease secreted from? (2)
Pepsin- Stomach (wall)
Trypsin- Pancreas
Where does Protease act? (2)
Stomach, Duodenum (ileum)
Where is lipase secreted from?
Pancreas
Where does the Lipase act?
Duodenum
What is the function of hydrochloric acid in gastric juice (2)
- kills harmful microorganisms in food
- provides and acidic pH for optimum enzyme activity (proteases)
What is the purpose of Bile? (2)
- Emulsifies fat
- Neutralizes the acidic conditions the material brings from stomach (to create a suitable pH for enzyme action)
Why does Bile emulsify fats
increase surface area for chemical digestion
