B3: levels of organisation and the digestive system. Flashcards
What is needed to see if starch is present
Iodine solution(changes from brown to BLUE/BLACK
What is needed to see if simple sugars are present?
Benedict’s solution(goes brick red if sugar is present)
What is needed to see if lipids (fat) is present?
Ethanol(milky-white if lipids are present)
What is needed to see if protein is present?
Biuret reagent(goes purple if protein is present)
What is an organ system?
Groups of organs that all work together to preform specific functions. They work together to form organisms.
What are some examples of organ systems in the human body?
- digestive system
- circulatory system
- gas exchange system
What is a tissue?
A group of cells with similar structure and function.
What is an organ?
Collections of tissues preforming specific functions.
Eg the stomach contains several tissues each with a different function in the organ.
What is the enzyme that breaks down starch
Amylase
What is the function of the pancreas?
To control glucose levels. Insulin is released when glucose levels rise after eating.
What is the function of the gall bladder?
To store bile.
What is the function of the stomach?
To break down insoluble molecules into smaller soluble molecules. Food is churned with digestive juices and acids.
What is a function of the liver
To produce bile.
What is the function of the large intestine?
To absorb water from undigested food.
What is the function of the small intestine?
To break down insoluble molecules into smaller soluble molecules and absorption.
What chemical elements does carbohydrates contain?
Carbon,hydrogen and oxygen.
What is an example of a carbohydrate with only one sugar unit.
Glucose
What are complex complex carbohydrates such as starch and cellulose made up of?
Long chains of simple sugar units bonded together.
What are lipids?
Lipids are fats and oils. They are the most efficient energy store in your body and an important source of energy in your diet.
What are lipids made out of?
3 fatty acid molecules and one glycerol molecule.
What is protein used for?
Building up cells and tissues of your body. They are also the basis of all your enzymes.
Between 15 and 16 percent of your body mass is protein.
What is a protein molecule made up of?
Long chains of small units called amino acids. There are about 20 types of amino acids. Different arrangement of amino acids give you different proteins.
The chains are folded and coiled to make 3d shapes. The bonds that hold these shapes are very sensitive tho the temperature of pH and can be easily broken.
What is a simple sugar?
Carbohydrates that only contain one or two sugar units.
What are enzymes?
Large protein molecules. The shape is vital for the enzyme to function. The chains of amino acids are folded to produce a molecule with an active site that has a unique shape so it can bind to a specific substrate molecule.
Simple: made out of amino acids, has a particular shape to break down a particular substrate.
What is the lock and key model?
The substate of the reaction to be catalysed fits in the enzymes active site.
- The enzyme and substate bind together.
3: the reaction takes place, products are released from the surface of the enzyme.
(It can also join two smaller molecules together, not just break apart).
Metabolism
The sum or all the reactions in a cell or body.
Catalysts______ the rate of reaction without changing chemically themselves
Increase
Enzymes are _____
Biological catalysts.
Why do Enzymes catalyse specific reactions in living organisms ?
Due to the shape of their active site
The _______ binds to the ______ and the reaction is _____by the enzyme.
- Substrate
- Active site
- Catalysed
What does catalyse mean?
cause or accelerate (a reaction) without being used up(by acting as a catalyst)
Do enzymes change a reaction in any way?
No they just make it faster.
Different enzymes catalyse(speed up) specific types of metabolic reactions:
(Name the 3 ways)
1.Building large molecules from lots of smaller ones.(eg, building starch from glucose)
- Changing 1 molecule into another
(Eg, changing a simple sugar into another, like glucose to fructose) - Breaking down larger molecules into smaller ones. (Breaking down lipids to glycerol and 3 fatty acids)
What is each different types of reaction is controlled by what?
A different specific enzyme
Are enzymes killed when they are denatured?
No ,they are not living things make sure o use the word denatured instead of died.
How can you determine the rate of reaction in hydrogen peroxide?
Measuring the volume of oxygen produced over time.
A simple way to do a comparison of the inorganic catalyst and the enzyme is add a drop of washing up liquid to the hydrogen peroxide.
Add the inorganic catalyst or the enzyme(liver of potato) and MEASURE how quickly the foam produced by the bubbles of gas rises up the test tube.
What is volume
the amount of space that a substance or object occupies, or that is enclosed within a container.
How do you work out volume?
Length x width x heright
What does inorganic mean (in Biology)?
Of or pertaining to substances that are not of organic origin.
The decomposition of hydrogen peroxide to oxygen happens much ____ using a catalyst.
Faster
What temperature do most enzymes work best at?
37 degrees
Is it dangerous for a human enzymes to become denatured due to a high temperature?
Yes it can cause death
Do all enzymes work best at about 40 degrees?
No, it depends on the enzyme
Why does the change in pH effect the shape of a molecule?
The shape of an active site of an enzyme comes from forces between the different parts of the protein molecule.
A change in pH effects these forces, thats why it changes the shape of a molecule.
When an enzyme is denatured is it still a catalyst?
NO
Can a change in pH stop enzymes working completely?
Yes
Can a change in pH make an enzyme work more efficiently?
Yes
What is pH?
A scale of acidity
Where do most enzymes work?(not ones in digestive system)
Inside the cells of the body controlling chemical reactions.
Where do enzymes involved in the digestive system work?
Outside the cells.
Where are enzymes involved in the digestive system produced?
In specialised cells in glands.
Such as salivary glands and pancreas.
Ehat are salivary glands?
The salivary glands make saliva and empty it into your mouth through openings called ducts. Can also stop infections in the mouth
Where is amylase produced?
salivary glands and the pancreas.
Where does amylase work?
Small intestine and mouth
Where is protease produced?
Stomach, and small intestine
Where does protease work?
Stomach and small intestine.
Metabolism
The sum or all the reactions in a cell or body.
Catalysts______ the rate of reaction without changing chemically themselves
Increase
Enzymes are _____
Biological catalysts.
Why do Enzymes catalyse specific reactions in living organisms ?
Due to the shape of their active site
The _______ binds to the ______ and the reaction is _____by the enzyme.
- Substrate
- Active site
- Catalysed
What does catalyse mean?
cause or accelerate (a reaction) by acting as a catalyst.
Do enzymes change a reaction in any way?
No they just make it faster.
Different enzymes catalyse(speed up) specific types of metabolic reactions:
(Name the 3 ways)
1.Building large molecules from lots of smaller ones.(eg, building starch from glucose)
- Changing 1 molecule into another
(Eg, changing a simple sugar into another, like glucose to fructose) - Breaking down larger molecules into smaller ones. (Breaking down lipids to glycerol and 3 fatty acids)
What is each different types of reaction is controlled by what?
A different specific enzyme
Are enzymes killed when they are denatured?
No ,they are not loving things make sure o use the word denatured instead of died.
How can you determine the rate of reaction in hydrogen peroxide?
Measuring the volume of oxygen produced over time.
A simple way to do a comparison of the inorganic catalyst and the enzyme is add a drop of washing up liquid to the hydrogen peroxide.
Add the inorganic catalyst or the enzyme(liver of potato) and MEASURE how quickly the foam produced by the bubbles of gas rises up the test tube.
What is volume
the amount of space that a substance or object occupies, or that is enclosed within a container.
How do you worm out volume?
Length x width x heright
What does inorganic mean (in Biology)?
Of or pertaining to substances that are not of organic origin.
The decomposition of hydrogen peroxide to oxygen happens much ____ using a catalyst.
Faster
Where do lipase enzymes start to work?
Small intestine
Hydrochloric acid gives the stomach a ______ suitable for the protease secreted to work efficiently
Low pH
The enzymes made in pancreas and small intestine work best in____
Alkaline conditions
What are alkaline conditions?
. alkaline conditions, are a higher pH like 7 not to sure
What is bile released through?
Bile ducts
What does bile do?
Neutralises acids but more importantly gives a bigger surface area to help digest fats (emulsifies)
Is the bile duct an enzyme?
No
What does bile do?
It emulsifies the fat into tiny droplets, which increase the surface area for the lipase
Increases rate of digestion.
What does alkaline bile do?
Neutralises acid and gives a high pH so the enzymes from the pancreas can work well.
What does alkaline mean?
having a pH greater than 7
What does hydrochloric acid do?
Gives the stomach a low pH suitable for the protease that are there to work efficiently.
What is pepsin?
the chief digestive enzyme in the stomach, which breaks down proteins into polypeptides.
What is the optimal pH for pepsin?
About pH 2
At what pH does pancreatic amylase work best?
pH8
Where is amylase made?
In the salivary glands and pancreas
Where does the enzymes in the pancreas go?
Small intestine.
Were is protease produced?
Stomach
Small intestine
Pancreas
The breaking down takes place in the stomach and small intestine
Where re fats broken down?
Small intestine
Where can you find pepsin?
In the lining of the stomach (protease enzyme)
What condition does bile produce?
Alkaline conditions
How do you know if fats are present
Add ethanol,Food turns cloudy white
When the substrate comes into contact with the active site what happens?
The substrates bonds are broken.
What does it mean when cells differentiate?
Becoming specialalised to carry out particular functions
What are the glands in the diggestive system?
Pancrease and silvery glands
Colour change for Benedict’s solution?
Blue to brick red
Colour change for iodine?
Yellow/brown-blue-black
Colour change for biuret reagent?
Blue to purple
Colour change for ethanol?
Colourless-cloudy white
Adaptations of small intestine
Contain lots of villi and microvilli
What does villi in the small intestine do?
Massively increase the surface area for the absorption of molecules
Where is microvilli found?
On the surface of the villi
What do microville do?
Increase the surface area even further
How does ville increase the concentration gradient?
Villi have a very good blood supply so the bloodstream rapidly removes the products of digestion
How does the villi ensure there is a short diffusion path?
They have a short membrane
What does all the features of the villi mean?
There is a rapid rate of diffusion
What happens to any molecules that can’t be absorbed by diffusion?
They are absorbed by active trasport
What are buffer solutions used for(RP)
To control the pH
Describe th methord for the effect of pH on amyalse RP
-drop of iodine in spotting tiles
3 test tubes(2cm cubed of starch in one, 2cm cubed of amylase in another, 2cm cubed pH 5 buffer solution)
- place all three in water bath for 10 mins for solutions to reach 30 degrees
- combine 3 solutions and mix with a stirring rod
- every 30 seconds put drop of solution in iodine(will turn black)-do it until colour change to orange/blue
Repeat with different pH buffers
