Biology - Tripple Flashcards
If a cell is short of water what happens?
The solution inside will become more concentrated and the solution outside will become more dilute this would cause more water to move into the cell
What is osmosis?
Is the movement of water molecules across a partially permeable membrane from an area of high water concentration to an area of low water concentration
If a cell has too much water what happens?
The solution inside the cell becomes more dilute whereas the solution outside the cell becomes more concentrated this means water will leave the cell
If a cell is put in pure water what happens?
It will burst as water will be continually going into the cell
If the cell is pit in a salt solution?
The cell will shrink as all the water will leave the cell
Why do plants need osmosis?
To support their stem and leaves
How do plants use osmosis to support their stem and leaves?
Water moves into the plant cell by osmosis this causes the vacuole to swell and press the cytoplasm against the plant cell wall which causes the pressure to grow until no more water can enter the cell making it rigid and hard
What is active transport?
The movement of substances against a concentration gradient or across a cell membrane using energy from respiration
What do root hair cells in plants do?
On surface of plant roots
Gives the plant a big surface area for absorbing water and mineral ions from the soil
When is active transport used in humans?
It is used when there is a low concentration of nutrients in the gut but a high concentration in the blood
What do sports drinks do?
Water and ions replace those lost in sweat
Sugar replaces sugar lost in muscles
Name the main adaptations for exchange processes
Thin - short distance to diffuse
Large surface area - lots of substances can diffuse at once
Lots of blood vessels
Ventilation- move air in and out
How do plants gas exchange?
Air space - co2 diffuse out and 02 in easily so photosynthesis can happen quickly
Stomata - allows gases to move in and out
O2 and water vapour - diffuse out and water vapour can be lost through leaves
Guard cells - control opening and closing of stomata
Shape - flattened to increase surface area
Waxy cuticle - stops water loss
What do the alveoli do in the lungs?
- tiny air sacs give more surface area so there is more effective diffusion and they have a rich blood supply thus increasing the concentration gradient
- spherical shape gives more surface area
- very thin walls give a short distance making diffusion easier
What is the thorax?
It is the top part of the body
How does air enter the lungs? The system
Goes through the trachea
Then splits into two tubes called bronchi
Bronchi splits into smaller tubes called bronchioles
Bronchioles end in alveoli
How does breathing in work?
Intercostal muscles and the diaphragm contract
Thorax volume increases
Thus decreasing the pressure drawing air in
How does breathing out work?
Intercostal muscles and diaphragm relax
Thorax volume decreases
Thus increasing the pressure forcing air out
What is negative pressure?
A system where the external pressure is lower than the internal pressure
What is positive pressure?
A system where the external pressure is higher than the internal pressure
Is an iron lung negative or positive pressure?
Negative
How does an iron lung work?
Patient put inside long vacuum
Air pumped out the pressure is dropped this causes lung expansion and air is drawn in
Air pumped in and the pressure is increased this causes the lungs to decrease and air is drawn out
How does positive pressure work?
Air is pumped into the lungs this expands the ribcage and when they stop pumping air is pushed back out of the lungs
How does a plant transport food?
Phloem
Through phloem tubes which are made out of living cells with small holes in the end to allow things to flow through
Transport food made in the leaves to growing regions and storage organs
Goes in both directions
How does a plant transport water?
Xylem
Xylem tubes are dead cells joined end to end with no end walls between them and one whole down the middle
They carry minerals and water in a transpiration stream from the roots to the steam and leaves
Only goes up
What is transpiration?
The loss of water vapour from the leaves of the plant through the stomata when they are opened to allow gas exchange for photosynthesis
What is a transpiration stream?
The movement of water through a plant from the roots to the leaves as a result of of water loss by evaporation from the surface of the leaves
How do you control water loss?
Wilt so surface area is reduced
Waxy layer
Stomata closes
Describe the double circulation system?
- Deoxygenated blood goes towards the lungs where its given oxygen the it goes back to the heart
- Oxygenated blood goes to the body and then returns to the heart as deoxygenated blood
Describe the heart?
Pumping organ Made up of muscle Has valves to prevent it from going backwards right atrium Left atrium Right ventricle Left ventricle Coronary artery supplies it with oxygen
How does the heart work?
- Deoxygenated blood flows into the right atrium from the vena cava
- The atrium contracts and the blood is forced into the right ventricle
- The right ventricle contracts and the deoxygenated blood leaves the heart through the pulmonary artery
- The deoxygenated blood is taken to the lungs and comes back as oxygenated
- The blood flows into the left atrium from the pulmonary vein
- The left atrium contracts pushing the blood into the left ventricle
- The left ventricle contracts pushing the blood aorta
- Aorta goes the other parts of the body
- Repeats itself
Describe an artery?
Thick layers of muscle to make it strong and elastic fibres so it can stretch and spring back into place this means its able to pump at high pressures
Small lumen
Thick walls
Describe an vein?
Joined up capillaries
Not as thick as it has a low pressure
Bigger lumen to help blood flow and keep pressure low
Valves to keep blood flowing in the right direction
Describe a capillaries?
Arteries branch into them
Tiny
Carry blood close to every cell so they can exchange easily
Permeable walls for diffusion
Supply food and oxygen take away carbon dioxide
One cell thick to increase rate of diffusion
Name the things that are in the blood
Platelets
Red blood cells
White blood cells
Plasma
What is the purpose of the red blood cell? and describe it
Carry oxygen
Has a red pigment called haemoglobin this reacts with the oxygen to form oxyhemoglobin and in body tissues this splits up again
NO NUCLEUS
Large surface area for absorbing oxygen biconcave
Describe white blood cells
Change shape to eat unwelcome microorganisms
Have a nucleus
Produce antibodies and antitoxins
Bigger than red blood cells
What do platelets do? and describe them
Help blood clots
Small fragments of cells
No nucleus
Help blood clot at a wound this stops blood pouring out and microorganisms pouring in
Lack of platelets can cause excessive bleeding and bruising
What does plasma do?
Carries everything
What is saline used for?
Artificial blood
A salt solution which has no oxygen or food and replaces the lost volume of blood to keep blood pressure normal
What is the general use of artificial blood?
To keep volume the same so that the blood pressure stays the same and so the red blood cells can be pumped around the body
What is a per-fluorocarbon?
A non reactive chemical that carries dissolved gases around the body
It does not contain cells so can get to the most swollen places
What are the benefits and costs to PFCs?
\+ can be kept a long time \+ don't carry disease - don't dissolve water so its hard getting them into the blood - don't carry as much oxygen - side effects - break up easily
What are the advantages and disadvantages of an artificial heart?
+ less likely to reject it as its not made out of tissue
+temporary or permanent
- lead to bleeding and infection
- don’t work as well as a natural heart
- parts can fail and the electric motor can fail
- drugs taken to thin blood and prevent a blood clot which could lead to a stroke
What is a stent?
A metal mesh insterted inti the arteries to widen them and make sure blood can pass through them easily
+ lower risk of heart attack
- stents can irritate the artery producing scar tissue
- take drugs to stop blood clotting
What is homeostasis?
It is the maintenance of a constant internal environment
Whats are the things that effect the body temperature?
Energy produced in muscles
Fever
External temperatures
How does the body control temperature?
With the thermoregulatory centre in the brain it contains receptors that are sensitive to the temperature of the blood flowing through the brain and it receives impulses from the skin telling it about the skin temperature
What happens when you are too hot?
- hairs lie flat
- sweat produced by glands which evaporate from the skin which cools you down
- vascodilation blood vessels become larger and closer to the surface of the skin so heat can be lost by radiation easily
What happens when your too cold?
- hairs stand up this would translate a layer of insulating
- shivering the muscles contract this requires respiration which releases some energy which warms the body
- vasoconstriction the blood vessels constrict and close off the blood supply to the skin this reduces the energy lost by radiation through the skin
What are the main functions of the kidney?
Remover urea
Adjust the ions in the blood
Adjust the water content in blood
How is urea produced?
Proteins cannot be stored in the body so excess amino acids are converted into fats and carbohydrates which can be stored. This happens in the liver and the product of the reactions is urea
How is urea removed?
Urea is poisonous and its released into the blood stream by liver the kidney filters it out of the blood then its stored in the bladder in the form of urine and then its excreted
What happens if the ion content is wrong?
It can cause too little or too much water enter the cells during osmosis this can damage cells
How are ions removed?
Lost in sweat or removed by kidney
How does the body control water content?
Liquid consumed
Amount sweat out
Amount excreted
What happens to water on a cold day?
Don’t sweat this increases urine its pale and dilute
What happens to water on a hot day?
This increases sweat and decreases urine the urine is dark coloured and concentrated. It has to be replaced with food and water
What happens if the kidneys fail?
If kidneys don’t work waste substances in the blood increase and then the body will no longer be able to control water and ions resulting in death
Why is urine yellow?
Urine is the result or urobilins which are yellow pigments that comes from the breakdown of haemoglobin in the liver
How does the dialysis work?
In a dialysis machine the persons blood flows alongside a selectively permeable barrier surrounded by dialysis fluid.
The dialysis fluid has the same concentration of dissolved ions and glucose as healthy blood this means useful dissolved ions and glucose wont be lost from the blood during dialysis.
Its permeable to ions and waste substances but not big molecules such as proteins so only waste substances diffuse across the barrier it then goes through an bubble trap to get rid of any bubbles
- 3-4 hours for 3 times a week can cause blood clots and infection
How does a kidney transplant take place?
- Donor with a tissue type that closely matched the patient is chosen, the tissue type is based on the antigens - proteins that are on the surface of most cells
- The patient is then given immunosuppressant drugs that suppress immune system so it will not attack the transplanted kidney
What are the advantages and disadvantages of having a kidney transplant?
- donor kidney could be rejected due to foreign antigens
- suppressing the immune system makes the person more vulnerable to other illnesses
- doesn’t last forever
+ don’t have to inject insulin
Why might some people donate kidneys?
- developing countries may donate kidneys to pay for things
- people may have been effected by kidney failure through another family member so may decide to become a kidney donor or organ donor
- both transplants and dialysis cost a lot
What happen when you are too cold?
Hypothermia - temperature falls below 35
- extreme tiredness and not wanting to move
- cold skin, greyish-blue face which is puffy and has blue lips
- drowsy and slurred speech
- eventually you stop shivering and your enzymes stop working
How do you control blood glucose?
- insulin and glucose
- glucose levels must be kept steady the body does this by the pancreas secreting the hormones insulin and glucagon
What happens when your blood glucose is too high?
- insulin is added
- insulin is secreted in the pancreas and added to the blood. The glucose is removed by the liver and the insulin turns the glucose into glycogen therefore the glucose has been reduced
What happens when your blood glucose level is too low?
- Glucagon is added
- glucagon is secreted by the pancreas and added to the blood and mixed with the glucose. Glucose is added to the liver along with glucagon which turns the stored glycogen back into glucose therefore the glucose level is increased.
What causes type 1 diabetes?
Type 1 diabetes is caused by the pancreas not making enough or any insulin, this results in the blood glucose level rising to levels that can kill them
How do you treat or control type 1 diabetes?
- limit the intake of food riched with carbohydrates
- regular exercise lowers blood glucose level and keeps heart and blood vessels healthy
- insulin therapy - inject insulin at mealtimes so when the food is digested the glucose is removed effectively
Amount injected depends on persons diet and how much they exercise and its not as controlled as having a working pancreas and they will still have a long term illness - pancreas transplant, they wont have to inject themselves again but they have to take immunosuppressant drugs and it may reject the tissue
- stem cells
What causes type 2 diabetes?
Obesity and lack of exercise so the pancreas makes less insulin and cells stop responding to insulin properly.
How do you fix type 2 diabetes?
- balanced diet with controlled carbohydrates
- lose weight
- do regular exercise
- take drugs to help insulin work better in body cells or to help pancreas make more insulin or reduce the amount of glucose absorbed in the gut
