The Digestive System And Enzymes Flashcards
The breakdown is catalysed by:
Enzymes
Digestion:
Is the breakdown of food into soluble products, which are then absorbed into the body.
It happens in the digestion system where food is broken down mechanically and by digestive enzymes.
Big molecules:
Starch, proteins and fats are too big to pass through the walls of the digestive system
Small molecules:
Sugar, amino acids, glycerol and fatty acid can pass easily through the walls of the digestive system
Carbohydrases: e.g. amylase
Digest starch to sugars
Proteases: e.g. pepsin
Digest proteins to amino acids
Lipase:
Digests fat to fatty acids and glycerol.
Mouth:
Food is moistened with saliva from the salivary glands
The salivary glands produce amylase enzyme in the saliva, which breaks down starch
Food is chewed to form a ball of food before being swallowed
Liver:
Where bile is produced
Bile neutralises stomach acid and emulsifiers fats
Oesophagus:
A tube takes food from the mouth to the stomach
It’s lined with muscles that contract to help the ball of food move along, by peristalsis
Stomach:
Pummels the food with its muscular walls
Provides the protease enzyme, pepsin
Produces hydrochloric acid to kill bacteria and to give the right pH for the protease enzyme to work
Gall bladder:
Bile is stored, before it’s released into the small intestine
Pancreas:
Produces protease, amylase and lipase enzymes.
Releases these into the small intestine.
Small intestine:
Produces protease, amylase and lipase enzymes to complete digestion.
Where the ‘food’ is absorbed out of the digestive system into the body.
Large intestine:
Where excess water is absorbed from the food
