Digestion system Flashcards
Functions, enzymes and features of the digestive system
What is digestion?
The breakdown of insoluble molecules into smaller soluble molecules. That can be assimilated and used,
What’s mechanical digestion?
Examples: Teeth and peristalsis
Muscular movements pushing food along the oesophagus into the stomach.
What’s villi and what do they do?
They provided the intestine with a large surface area.
This means more food can be absorbed into the blood stream.
Villi have a good blood supply
What are the three stages of digestion?
1) Mechanical digestion
2) Saliva is added
3) Peristalsis moves food down the oesophagus
3 types of enzyme?
protease
lipase
Amylase
What are gastric juices made of?
Hydrochloric acid and pepsin
What’s pepsin?
An enzyme that breaks down protiens
What’s an example of a helping enzyme?
Bile
what’s bile?
A substance produced by the gallbladder that breaks down lipids (fats) into small droplets.
What’s the process of breaking down lipids into droplets called?
emulsification
What do salivary glands do?
Produces saliva
Moistens up food and contains enzymes
What does the oesophagus do and what is it?
They are made of muscular walls
Moves food to stomach
3 features of the stomach
Produces enzymes
produces hydrochloric acid
Strong muscular walls
What does the stomach do?
Mixes food
kills harmful microbes
Provides optimum PH
Digests food
What does the liver do?
Produces bile
Bile neutralises stomach acid
Stores carbohydrates (as glycogen)
Emulsifies fats
What is the gall bladder?
Small bag-like structure
stores bile
What does the pancreas do?
Produces enzymes that help digest food in the small intestine
What does the small intestine do?
Produces enzymes
Digests food
Absorbs soluble food
Features of the small intestine
Large surface area
It contains villi and microvilli
Features of the large intestine
Has specilised cells to absorb fluid
What does the large intestine do?
Absorbs water
Solidifies waste
Where is amylase found?
The salivary glands
What does amylase do?
Breaks down starch into glucose (sugars)
What does lipase do?
Breaks down lipids (fats) into fatty acids and glycerol
What does protease do?
Breaks down proteins into amino acids
Where is protease found?
Stomach (gastric acids)
Pancreases
Wall of ileum
Where is amylase found?
Salivary glands
Small intestine
Pancreas
Where is lipase found?
Pancrease
Functions of the mouth
Begins digestion of carbohydrates
Mechanical digestion
Functions of the stomach
Begins digestion of small molecules
Example: Alcohol is absorbed
In an enzyme required practical what’s the dependant variable?
Time taken to stop changing colour
Functions of the small intestine
Continues digestion of carbohydrates and proteins
Begins digestion of lipids
In an enzyme required practical what’s the control variables?
Temperature
Concentration of starch
Volume of buffer
Volume of amylase
Concentration of amylase
