B3 - Organisation and the Digestive System Flashcards
food test for glucose
Benedict’s solution turns brick red when glucose is present
define tissue
a group of similar cells working together to perform a specific function
define organ
a group of different tissues working together to perform a specific function
define organ system
a group of organs working together to perform a specific function
list the hierarchy of things that make up an organism
smallest -> largest
- organelles
- cells
- tissues
- organs
- organ systems
- organism
What is the function of the liver?
producing bile
What is the function of the stomach?
Breaking down large insoluble molecules into smaller soluble molecules
What is the function of the small intestine?
Breaking down large insoluble molecules into smaller soluble molecules
And absorbing food
What is the function of the large intestine?
absorbing water from undigested food
an example of an enzyme that breaks down carbohydrates - what is the product
amylase (a carbohydrase) - it breaks carbohydrates into simple sugars
an example of an enzyme that breaks down proteins - what is the product
pepsin (a protease) - amino acids
what is the name of the enzymes that break down lipids - what is the product
lipase enzymes - fatty acids and glycerol
Where is amylase produced?
- salivary glands
- small intestine
- pancreas
Where is pepsin produced?
- gastric glands in stomach
- small intestine
- pancreas
Where is lipase produced?
- small intestine
- pancreas
define metabolism
the sum of all the reactions in the cell or the body
what are enzymes
they are organic catalysts that speed up reactions
define exothermic reaction
transfers energy to the surroundings
define endothermic reaction
transfers energy from the surroundings
what does it mean if an enzyme is denatured
the active site of the enzyme changes shape so it can no longer catalyse reactions
lock and key interpretation of enzyme action
- the enzyme has a specific active site that binds with the substrate, like a key.
- the active site is complementary to the substrate - the fit is exact
- enzymes are specific meaning they catalyse a specific reaction
define quantitative and qualitative
quantitative - can be measured
qualitative - cannot be measured
define optimum condition of an enzyme
the temperature and pH of which a specific enzyme catalyses the most reactions
2 functions of bile
- emulsifies fat to form smaller droplets to increase surface area for enzyme catalysation
- neutralises stomach acid (8 pH)
where is bile stored
gallbladder
How do you test for sugar?
Get a test tube and add a few bits of the food you’re testing on into it. Then add a few drops of benedict’s solution into it. After place in a controlled heated water bath . Wait for 5 minutes then take it out. If the colour changes from blue to brick-red, green or yellow then sugar is present depending on how much sugar there is.
How do you test for starch?
Take a test tube and add your food sample into it with a few drops of iodine solution. Then gently shake it and if the solution turns from yellow-brown to black or blue-black then starch is present
How do you test for lipids?
Get a test tube and put a sample of the food you’re testing on. Then use a pipette to add ethanol into the test tube. If the solution turns from clear to cloudy white then lipids are present.
How do you test for protein?
Add a few drops of the food and biuret reagent into a test tube. Then mix the solutions up by gently shaking it. If protein is present then it’ll change from blue to purple.
