Organisation Flashcards
Where are carbohydrates found and what do they do
Found in starchy foods. Provides energy for chemical reactions
3 uses of lipids (fats and oils)
Provides energy
Insulation
Protects organs
What are vitamins A,C,D needed for?
Vitamin A- Good vision and healthy skin
Vitamin c - prevent scurvy
Vitamin d - absorb calcium
Why does increase of temperature only accelerate the rate of enzyme action until 37 degrees
High temperature starts to break apart bonds holding the enzyme together.
The active site begins to change shape.
If it changes shape too much the active site of the enzyme won’t be able to bind to the substrate.
Enzyme denatured
Why does increase of pH only increase rate of enzyme action until 7 pH
High pH causes some of the bonds holding the enzyme together to start to break
Active site begins to shape (enzyme action will still work but at a slower rate)
Then eventually the active site changes so much that the substrate can’t fit.
Enzyme has been denatured
What does fibre do
Help food move through our intestines properly.
What is the Locke and Key model
Scientists thought that the substrate has to fit perfectly into the active site like a key fits perfectly into a dood
What is the induced fit model
The enzymes active site actually changes shape slightly as it binds to the substrate
Order of the digestive system
Mouth > Stomach > Small intestine > Large intestines
What happens in the mouth in the digestive system
Chew to digest food
Saliva is from salivary glands helps, releases salivary amylase which breaks down carbohydrates.
What happens in the stomach in the digestive system
Contracts muscular walls to push and mix food
Produces pepsin which is a protease enzyme which breaks down proteins.
Produces hydrochloric acid which kills bacteria.
What happens in the small intestine in the digestive system
Food is absorbed into the bloodstream
Produces enzymes to help digestion
What happens in the large intestine in the digestive system
Absorbs excess watery food. Leaves poo and wee.
What does the pancreas do in the digestive system
Creates most digestive enzymes and pushes them into the small intestines in the form of pancreatic juices.
What does the gall bladder do in the digestive system
Releases bile into the small intestine
What are the 2 main roles of bile in the small intestine
Neutralises acid from the stomach, does this to make pH levels more ideal for the digestive enzyme to function.
Emulsifying fats (breaks down fats into droplets). It does this so there’s a bigger surface area for digestive enzymes to work on
How is the villi in the small intestine adapted for its function
Increases surface area. Digested food can be absorbed into the bloodstream quicker.
Single layer of surface cells. Nutrients can diffuse over a shorter distance
Very good blood supply. To keep a concentration gradient
What is haemoglobin
The protein in red blood cells which allows them to transport oxygen around
What does protease do and where is it made?
Breaks down proteins into amino acids
Made in:
stomach
Pancreas
Small intestine
Where is Amylase made and what does it do?
Made in:
Salivary glands
Pancreas
Small instestine
Breaks down starch into smaller sugars (maltose molecules)
What does maltose do
Breaks down maltose molecules into glucose
What does lipase do and where is it made
Breaks down lipids (fat and oils) into fatty acids and glycerol.
Made in:
Pancreas
Small intestine
What is the test for sugars (with explanation)
Benedict’s test
Put 10 drops of Benedict’s solution into 5cm^3 of the sample
Put it in a 75 C water bath
If sugar is present it green, yellow or brick red.
What is the test for starch
Iodine test
Add iodine solution to 5cm^3 of the sample
It will immediately turn to a browny orange colour
When shaken it will turn to a blue/black colour of starch is present
What is the test for protein
Biuret test
Add 2cm ^3 of the biuret solution to a test tube with 2cm^3 of the solution
It will turn blue immediately
When shaken the solution will turn punk or purple if protein is present
What is the test for lipids
Sudan III test
Add 3 drops of Sudan solution to the sample
Bright red layer will appear on the top of the test tube when shaken if lipids are present
How are the alveoli adapted for gas exchange
Single cell thin walls - shorter distance for diffusion which increase the rate of diffusion
Very large surface area
Alveoli walls are moist which allow gases to dissolve - also increases the rate of diffusion
Explain how gas exchange works in the alveoli
Oxygen diffuses out of the alveoli into the blood in the capillaries
Carbon dioxide diffuses out of the blood in the capillaries into the alveoli which we then breathe out.
How to work out breathing rate
Number of breaths taken / number of minutes
Function of arteries
Carry blood away from the heart to the body
3 adaptations of artery
Muscle tissue provides strength and allows the arteries to direct blood flow
Elastic tissue allows the tissue to stretch and recoil
Narrow lumen which keeps the blood pressure high
Function of capillaries
Exchange nutrients and waste products with the tissues
2 adaptations of capillaries
Single cell thick walls which means shorter distance for diffusion
Permeable walls which means substances are able to move through them
Function of vein
Carry blood from the body back to the heart
Describe the structure of vein
Thin walls and wide lumen
Valves
In what order does blood flow through the three types of blood vessels
Heart arteries capillaries veins heart
Adaptations of red blood cells
No nucleus. More space for oxygen and haemoglobin
Shaped like a biconcave disk, more surface area for absorbing oxygen
