3.2 Human Digestive system Flashcards
What does the mouth do
physically breaks down food into smaller pieces
what does the salivary gland do
makes saliva that contains enzymes called amylase
What does the gullet do
tube that carries food from throat to stomach
What does the stomach do
Organ where food is churned with digestive juices and acids (protease and hydrochloric acid)
What does the pancreas do
Makes and releases digestive juices containing the enzymes to break down your food
What does the liver do
Produces bile into small intestine where it helps to digest fats
What does the gall bladder do
Stores bile
Small intestine
where small digested molecules are absorbed into the blood stream
Large intestine
Organ where water passes back into body leaving solid waste
Anus
Muscular ring opening to get rid of feces
Why does the stomach contain acids
Provide the optimum conditions for enzymes to work/kill any microorganisms that may be present in the food
What food component does bile digest
Lipids
What does the rectum do
Collects your feces until it is time to release it
Describe what happens to the structure of food molecules during digestion/ give def of digestion
Large insoluble molecules of food break down into smaller soluble molecules
Why cant you absorb food molecules
big , insoluble
Give example of glands
pancreas, salivary gland
What do the enzymes break down
Large insoluble food molecules into smaller soluble ones
How long is normally the digestive system
6-9m
Explain how the small intestine is adapted to perform its function
Increase surface area as it is covered in villi
Villi contain blood capillaries to carry away the absorbed food molecules, increase diffusion gradient
These adaptations increase the rate of absorption
Digestive system def
Organ system where food is digested and absorbed
What is the function of the digestive system
To turn large, insoluble molecules into small, soluble molecules that can be used by the body for energy, growth and repair
What does the liver do
It produces bile, which helps in the digestion of lipids
Using the digestive system as an example, explain how organs in an organ system rely on each other to function properly
Each part of digestive system relies on preceding parts.
Stomach relies on mouth, teeth, and salivary glands to deliver chunks of
chewed food.
Small intestine depends on stomach to continue digestive process
and on enzymes made by pancreas to help with the digestive process.
Large intestine can only deal with remains of food already digested in
the small intestine (soluble molecules absorbed into blood, leaving
waste material and water),
absorbing water and removing faeces from body.
Explain what a protein is
Molecule made up of long chains of amino acids
Describe the main similarities and differences between carbohydrates, lipids and proteins
similarities:
• vital components of a balanced diet
• contain carbon, hydrogen, and oxygen
• large molecules made up of smaller molecules joined together
differences:
• carbohydrates made up of sugar units
• lipids made up of fatty acids and glycerol
• proteins made up of long chains of amino acids
• lipids insoluble in water
• proteins contain nitrogen
Explain why lipids can either be fats or oils
Lipids are made up of three molecules of fatty acids joined to a
molecule of glycerol.
Different combination of fatty acids
determines whether lipid is solid (fat) or liquid (oil).
Explain how simple sugars are related to complex carbohydrates
Complex carbohydrates are made up of long chains of simple sugars
joined together.
Simple sugars are basic units of complex carbohydrates.
