The Digestive System Flashcards
What is a tissue?
A group of cells with similar structure and function working together e.g. muscle glands and epithelial tissue.
What is an organ?
A group of different tissues that work together to perform a certain function e.g. stomach, muscular tissue-contracts to move food, glandular tissue-makes digestive juices, epithelial tissue-lines the stomach
What is an organ system?
A group of organs working together to perform a certain function e.g. digestive system
What breaks down starch?
Amylase
What breaks down proteins?
Protease
What breaks down lipids?
Lipase
What is bile?
Produced in the liver stored in the gall bladder.
It neutralises the stomach acid.
It emulsifies fats e.g. breaks it into tiny droplets to speed up digestion.
What do salivary glands do?
Produce amylase (digestive juices)
What does the mouth do?
mechanical breakdown of food to increase surface area for enzymes
What does the stomach do?
It pummels the food
produces pepsin (protease)
produces hydrochloric acid to kill bacteria and give correct pH for protease or pepsin.
What does the liver do?
Where bile is produced
What does the gall bladder do?
Stores bile
What does the pancreas do?
Produces protease, amylase and lipase
What does the small intestine do?
Produces protease, amylase and lipase
absorbs digested food into the blood
What does the large intestine do?
Absorbs water and excretes waste
What is the Benedict’s test?
Testing for sugars
positive=red
What is the iodine test?
Testing for starch
positive=blue/black
What is the Biuret test?
Testing for proteins
positive=pink or purple
What is the Sudan III test?
Testing for lipids
positive=bright red layer
What is the ethanol test?
Testing for lipids
positive=cloudy solution
What is a protein made up of?
Amino acids.
What is starch made up of?
Simple sugars
What is a lipid made up of?
Glycerol+fatty acids
What is an enzyme?
A catalyst produced by a living thing.
Large proteins made by cells and folded into unique shapes.
What is a catalyst?
A substance which increases the speed of a reaction without being changed or used up.
How does an enzyme work?
Catalyse one specific reaction
every enzyme has an active site which fits to the substance involved In the reaction e.g. lock and key
What is the induced fit model?
The active site of an enzyme changes shape slightly as the substrate binds to it
Enzyme conditions?
Enzymes have an optimum temperature and optimum pH
if it is too hot bonds break and enzyme denatures because it’s active site has changed shape. This also happens if the pH is too high or too low.
