B3 Organisation and the digestive system Flashcards
What is digestion
The process of breaking down large insoluble molecules in your food into small soluble molecules
What is the function of the stomach
To digest food and temporarily store it
Produces digestive acids
What is the function of the small intestine
To help further digest food coming from the stomach
What is the function of the large intestine
Turns food waste into stool
What is the function of the kidneys
Removes waste and extra fluid from your body
What is the function of the liver
Processes blood and breaks down, balances and creates nutrients
Bile is produced
What is the function of the gall bladder
Stores bile
What is an enzyme
A biological catalyst that speeds up chemical reactions in living organisms
They are large protiens
How do enzymes work
They have an active side with a specific shape and a specific molecule fits into the active side where the chemical reaction takes place
The shape is very important and only one sort of enzyme will work on each substrate
What is the active site
The part of the enzyme where the reaction takes place
They have a specific shape so that a specific substrate fits into it (Lock and key)
What is the substrate
The molecule that fits into an enzymes active site and reacts to form a product or products
What is the role of a carbohydrate
What is it made from
Used in cellular respiration to provide energy
Made from simple sugars
What is the role of lipids
What is it made from
An energy store, used to make hormones
Fatty acids and glycerol
What is the role of proteins
What is it made from
Growth repair and maintenance
Amino acids
What is the test for sugars (glucose)
Describe the process
Benedict’s test
Add solution and benedict’s solution to a test tube
Heat it
If sugars are present there will be a colour change from blue to brick red
What is the test for starch
Describe the process
Iodine
Add a few drops of iodine to sample
If starch is present there will be a colour change from orange to blue/black
What is the test for lipids
Describe the process
Emulsion test (Ethanol)
Dissolve some of the test sample in ethanol
Pour this into a test tube of water
If lipids are present here will be a cloudy white emulsion
What is the test for protein
Describe the process
Biuret Test
Add biuret solution to test sample
If proteins are present the will be a colour change from blue to lilac
What is the function of hcl in the stomach
Adjusts pH to optimum for protease
What is the role of protease in the stomach
Speeds up the digestion of protein
What is the role of mucus in the stomach
Protects the stomach from auto digestion
Where is bile made, stored and released
Liver
Gall bladder
Small intestine
What is the role of bile
It is alkaline to neutralise stomach acid and make partly digested food pH 8 - the optimum pH for enzymes in the small intestine
It also emulsifies fats, meaning it breaks them down into smaller droplets (increased surface area) to increase their rate of digestion
What are the 3 digestive enzymes
Carbohydrase (amylase)
Protease
Lipase
Describe the use of carbohydrase in the body
Produced in the salivary glands, pancreas and small intestine wall
Site of action is the mouth and small intestine
Breaks down carbohydrates-Mainly starch
Describe the use of protease in the body
Produced in the stomach, pancreas and small intestine wall
Site of action is the stomach and small intestine
Breaks down proteins
Describe the use of lipase in the body
Produced in the pancreas and small intestine wall
Site of action is the small intestine
Breaks down fats
