Organisation Flashcards
Cells
Basic building blocks of all living organisms
Tissue
Group of cells with a similar structure and function
Organs
aggregations of tissues performing specific functions
Organ systems
Organs organised which work together to form organisms
Differentiation
Process by which cells become specialised for a particular job
When does differentiation occur?
During the development of a multicellurlar organism
Muscular tissue
Contracts to move whatever its attached to
Glandular tissue
Makes/secretes chemicals like enxymes/hormones
Epithelial tissue
Covers some parts of the body eg inside of gut
What tissues is the stomach made of? What do they do?
- Muscular tis. - moves stomach wall to churn up the food
- Glandular tis. - makes digestive juices to digest
- Epithelial tis. - covers outside/inside stomach
Glands
Produce digestive juices
Stomach
- Pummels food with its muscular walls
- Produces protease enzyme, pepsin
- Produces HCL to kill bacteria + give right pH for protease to work in
Liver
Makes bile
Small intestine
- absorbs soluble food mol.
- Produces protease, lipase, amylase
Large intestine
Absorbs water from undigested food, leaving faeces
Probs with increasing temp for reactions
- Requires lots of energy
- Speeds up unwanted reactions
- Cells might get damaged if its too high
Enzymes
- Biological catalysts that speed up useful chemical reactions
- Large proteins made from chains of AA
- Folded into unique shapes
What is a catalyst?
substance which increases speed of reaction w/o being changed/used up in the reaction
Lock and Key Theory
- Simpler model
- Substrate fits perfectly into active site
Active site
Unique shape where specific and complementary substrates only bind to
2 theories about enzymes
- Lock and Theory model
- Induced fit model
Induced fit model
- More realistic
- Enzyme actually changes shape slightly asit binds to substrate
- AS is complementary to substrate
What happens if the temp gets too hot for enzymes?
- Denature
- bonds holding enzymes break
- changes shape of AS so substrate wont fit
What is the optimum temp and pH?
- Temp they work best at is 37C / up to 40
- Mostly 7 but pepsin is 2
2 factors that affect enzymes?
- Temp
- pH
How does pH affect enzymes?
- Interferes with bonds holding it together
- Changes shape if too low/high, denatures it
What do digestive enzymes do?
Break down big molecules (starch,proteins,fats) into smaller soluble molecules so they can pass easily through walls of digestive system, allwoing them to be absorbed into the blood
What is amylase? What does it do? Where is it made?
- Exmaple of a carbohydrase
- Breaks down starch into simple sugars (glucose,maltosE)
- Made in the salivary glands, small intestine, pancreas
What is protease? What does it do? Where is it made?
- Breaks down proteins into AA
- Made in Stomach, SI and pancreas
What is lipase? What does it do? Where is it made?
- Breaks down lipids (fats ) into 3 fatty acids and 1 glycerol molecule
- Found in the pancreas and SI
3 digestive enzymes
- Amylase
- Lipase
- Protease
What is bile? Where is it produced, stored,released?
- Produced in liver
- Stored in gall bladder
- Released into SI
What does bile do?
- HCl in stomach makes pH too acidic for enzymes in SI to work props
- Bile is alkaline so it neutralises making conditions alkaline
- Enzymes in SI work best in alkaline conditions
- Also emsulfies fats - breaks it down to tiny droplets - gives a bigger SA for lipase to work on - faster digestion
Emsulsification
Bile emsulfies fats - breaks it down to tiny droplets - gives a bigger SA for lipase to work on - faster digestion
Where are digestive enzymes produced in and by?
By specialised cells in glands and gut lining
Salivary glands
- Produce amylase in saliva
Rectum
Rectum
Stores faeces before it leaves through the anus
What does iodine test for?
Starch
What does Benedict’s solution test for?
Reducing Sugars
What does biuret test for?
Proteins
What does emulsion test for?
Lipids
What colour does iodine change from and to when starch is present?
Orange-brown to Blue-black
What colour does biuret change from and to when protein is present?
Blue to purple
What colour does emulsion change from and to when lipid is present?
No emulsion to white emulsion (milky white)
What colour does Benedict’s solution change from and to when reducing sugars are present?
Blue to green to yellow/orange to red
Blue means no reducing sugars. It ascends from green to red.
Explain the method for biuret.
- 2cm3 to test tube of food solution
- As 3cm3 biuret solution to sample, gently shake it to mix
- Yes protein = blue to purple
- None = blue
Explain the method for iodine.
- Make sure that the food solution is not solid but a bit liquid, grind it with a pestle and mortar
- Put 5cm3 into test tube
- Add a few drops of iodine onto test tube and shake gently
- Results will be shown - orange/brown to blue/black
Explain the method for Benedicts.
- Add 5cm3 food solution to test tube
- Prepare water bath with 75 water
- Add 10 drops of Benedicts solution to test tube with a pipette
- Put test tube in water bath using a test tube holder and leave there for 5 min
- Make sure tube is pointing away from you
Explain the method for emulsion.
- Add food solution into test tube
- Add few drops of distilled water
- Add a few drops of ethanol
- Shake the test tube gently
- Results would be shown.
How do you prepare a food sample to test for a particular molecule?
- Break peice of food using a pestle and mortar
- Transfer ground up food to a beaker, add some distilled water
- Give a stir to the misxture with a glass rod to dissolve some of the food
- Filter solution using a funnel with filter paper to get rid of solid food bits
What is the Sudan III test for?
For lipids
Method for Sudan III test
- Use unfiltered sample of food you’re testing
- Add 5cm to test tube
- Use pipette add 3 drops of Sudan III stain solution to test tube and gently shake
- If sample has lipids, mixture will separate out into 2 layers. Top layer = bright red.
- If no lipids, no separate red layer will form at the top
Results for Sudan III test
- Sudan III stain lipids stains lipids
- Lipids present = 2 layers, top bright red separate layer
- Not present - no bright red layer at the top
Thorax
- Top part of body
- Seoarared from lower part of the body by diaphragm
What are the lungs protected by and surrounded by?
- Protected by ribcage
- Surrounded by pleural membranes
Where does the air travel when you breathe in order?
- Trachea
- Splits into 2 tubes called bronchi (one is a bronchus) going to each lung
- Bronchi split progressively into smaller tubes called bronchioles
- Reach small bags called alveoli where gas exchange happens
Where does gas exchange happen?
Alveoli
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Process of gas exchange
- Blood passing next to alveoli contains lots of CO2 and little oxygen
- Oxygen diffuses out of alveolus due to its high conc into the blood (low conc)
- CO2 diffuses out of blood into alveolus (low conc)
- CO2 is breathed out
- Blood reaches body cells - oxygen released from RBC (high conc) which diffuses into body cells (low conc)
- CO2 diffuses out of body cells (high conc) into blood (low conc)
- Blood carried back to the lungs to gain oxygen