B2: organisation Flashcards
Salivary glands
Produces amylase enzyme in the saliva
Oesophagus/ gullet
Transports food from mouth to stomach
Stomach
Pummels food with its muscular walls
Produces protease enzymes (pepsin)
Produces hydrochloric acid for -killing bacteria
-to give the right PH for the protease enzyme to work
Liver
Bile is produced
Pancreas
- Produces protease, amylase, lipase enzymes
* Release the enzymes into the small intestine
Gall bladder
Bile is stored before being released in to the small intestine
Large intestine
Excess water is absorbed from food
Small intestine
- Produces protease , amylase and lipase enzymes to complete digestion
- where the digested food is absorbed out of the digestive system into the blood
- absorbs soluble food molecules
Rectum
Faeces are stored
Testing for sugar benedicts solution
BENEDICTS SOLUTION
1) 5cm3 Of food sample into a test tube
2) water bath set to 75 °c
3) add 10 drops of benedicts solution to the test tube using a pipette
4) place test tube in to the water bath and leave for 5 minuets
5) if the food sample contains sugar it will change from yellow to brick-red
Testing for starch- iodine solution
IODINE SOLUTION
1) 5cm3 Of food sample to test tube
2) add a few drops of iodine solution and gently shake the test tube
If it contains stretch it will change from a browny-orange to a black
Testing for proteins - using biuret solution
1) 2cm3 Of food into a test tube
2) add 2cm3 Of biuret solution to the sample and mix the contents
3) if contains proteins it should change from blue to pink/ purple
Testing for lipids - using ethanol
1) add ethanol to the solution
2) shake the test tube and leave for a minute
3) pout ethanol in to a test tube of water
4 if the solution contains lipids it will turn and cloudy colour
Definition Of denatured
Where the shape of the enzyme changes due to PH or temperature and the bonds in the enzyme are broken which mean the lock and key mechanism will no longer work as the lock has changed shape and denatured
How does the heart pump blood
1) blood flows into the atria from the vena cava and the pulmonary vein
2) the atria contracts, pushing blood into the ventricles
3) the ventricles contract forcing the blood into the pulmonary artery and the aorta and out of the heart
4) blood flows to the organs through arteries and returns through veins
5) the atria fills again and the whole cycle starts over
Arteries
Carry blood away from the heart
1) the heart pumps the blood out at a high pressure so the artery walks are strong And elastic
2) contains thick layers of muscle to make them stronger and elastic fibres to allow them so stretch and spring back
Capillaries
Involved in the exchange of materials at the tissues
1) arteries branch into capillaries
2) carry blood close to every cell in the body to exchange substances with them
3) permeable walls so substances can diffuse in and out
4) supply food and oxygen and take away waste (CO2)
5) walls are one cell thick - increase the rate of diffusion by decreasing the distance over which it occurs
Veins
1) capillaries join up to form veins
The blood is at a lower pressure in the veins so the walls don’t need to be thick
2) valves to keep the blood flowing in the right direction
Platelets
- Small fragments of cells
- No nucleus
- Help blood clot at a wound to stop you from bleeding and to stop microorganisms from getting in
- Lack of platelets can cause excessive bleeding and bruising
Artificial heart advantages
ADVANTAGES: less likely to be rejected by the body’s immune system and they are made from metals or plastics so the body doesn’t recognise them as foreign and attack like with a living tissue
How do Faulty heart valves occur
Valves can be damaged or weakened by heart attacks , infection, old age
Biological valves
Taken from humans or other mammals
Medical valves
Man made
Benign Tumour
- Where a tumour grows until there is no room
- Tumour stays in one place rather than invading other tissues in the body
- Not normally dangerous and tumour isn’t cancerous
Malignant tumour
- Where the tumour grows and spreads to neighbouring healthy tissues
- Cells can break off and spread to other parts of the body by traveling in the blood stream
- Invade healthy tissues anywhere in the body and form secondary tumours
- Dangerous and can be fatal , cancers
Risk factors of cancers associated with life style
- Smoking
- Obesity
- UV exposure
- Viral infection
What cancers is smoking linked to
- Lung cancer
- Mouth cancer
- Bowel cancer
- Stomach cancer
- Cervical cancer
What cancers are obesity linked to
- Bowel
- Liver
- And kidney cancer
( second biggest preventable cause of cancer after smoking )
What cancers are UV exposure linked to ? And who are at a higher risk?
- Skin cancer
- People in sunny climates , people who spend a lot of time outside and people who use sun beds are at a higher risk of getting skin cancer
What cancers are linked to viral infections
- Some viruses have been shown to increase the chance of developing certain types of cancer
- The chance of becoming infected is sometimes due to lifestyle- spread through unprotected sex or sharing needles
Risk factors of cancer through genetics
- Inherit faulty genes meaning you’re more susceptible to cancer
- Mutations in the BRCA genes have been linked to an increased likelihood of developing Breast and ovarian cancer
Epidermal tissue in the leaf
- Covers the whole plant
* covered with a waxy cuticle, which helps to reduce water loss by evaporation
Palisade mesophyll tissue in the leaf
- This is part of the leaf where most photosynthesis happens
- has Lots of chloroplasts , meaning that they’re near the top of the leaf where they ca get most light
Spongy mesophyll tissue in the leaf
Contains big air spaces to allow gases to diffuse in and out of cells
Xylem and phloem in the leaf
•Transports water, mineral ions and food Around the plant
a network of vascular bundles , which deliver water and other nutrients to the entire leaf and take away glucose produced by photosynthesis, help support the structure
Meristem tissue in the leaf
- Found at the growing tips of shoots and roots and is able to differentiate into lots of different types of plant cells allowing the plant to grow
- are adapted for efficient gas exchange
Structures of the tissues that make up the leaf
- Epidermal tissues -
- upper epidermis-
- palisade layer-
- Xylem and phloem-
- Tissues -
Upper epidermis in leaf
is transparent so that light can pass through it to the palisade layer
Lower epidermis in leaf
Full of stomata which let CO2 diffuse directly into the leaf
Guard cells in the leaf
- Control the opening and closing of the stomata and adapter for gas exchange and controlling water loss in the leaf
- When the plant has lots of water the guard cells fill with it and go plump and turgid
- When the plant is short of water the guard cells lose water and become flaccid making the stomata close - stopping water vapour escaping
Air spaces in the leaf
The air spaces in the spongy mesophyll tissue increase the rate of diffusion of gases
Where is amylase enzymes made?
Salivary glands
Pancreas
Small intestine
What does amylase enzymes break down
Breaks down starch into maltose
Where is protease enzymes made
Stomach (pepsin)
Pancreas
Small intestine
What does protease enzymes break down
Breaks proteins down to amino acids
Where is lipase enzymes made
Pancreas
Small intestine
What do lipase enzymes break down
Breaks lipids down to glycerol or fatty acids
Bile
Produced in the liver
Stored in the gall bladder before being released into the small intestine