Unti 8 - Exchange And Transport In Animals Flashcards
Why must waste be excreted?
It can cause problems
What is the waste that your kidneys remove and why?
Urea, a poison produced by breaking down amino acids
What waste do your lungs get rid of?
CO2
What is oxygen and glucose needed for?
Aerobic respiration
What are dissolved food molecules and mineral ions needed for?
To produce new substances for your body
What 2 adaptations allow faster diffusion
Thin surfaces
Large surface area
What are small blood vessels called and an adaptation
Capillaries, one cell thick
What 2 substances diffuse out of the capillaries?
Oxygen, glucose
What do capillaries use to transport substances around the body
Blood
Why is it bad to have a too large volume of a cell
The cell cannot fill up with the materials that it need fast enough
What equation gives surface area: volume
Surface area / volume
As a cell gets bigger, what happens to the SA:V ratio
It gets smaller
Why is it bad to have a too small ratio for a cell
It cannot get enough raw materials fast enough (large volume)
What do lungs have to increase their surface area
Millions of alveoli
What do alveoli enable to happen
Increase the rate and amount of gas exchange
Describe the function of an alveolus
Blood enters from body with high concentration of CO2 and less O2
CO2 diffuses into the alveolus and O2 diffuses into the capillary
Blood returns to rest of body with more O2
Give 4 adaptations in the alveolus process
One cell thick alveolus wall
One cell thick capillary
Large surface area due to shape
Less CO2 and more O2 in alveolus
What is concentration
The amount of a substance in a certain volume
What is the equation for concentration
Mass / volume
What causes faster diffusion
A greater difference between the 2 concentrations
What type of relationship is the rate of diffusion and concentration difference
Directly proportional/ linear
How is rate of diffusion and surface area linked
Directly proportional
How is rate of diffusion and thickness of membrane related?
Inversely proportional
What does Fick’s law show
Rate of diffusion is directly proportional to SA x concentration/ thickness of membrane
How does blood flow in the circulatory system?
Away from heart through arteries, into capillaries and back to the heart through veins
Give 2 adaptations of arteries
Thick walls
Layer of muscle
Why do arteries have thick walls
To withstand the pressure from the heart pumping the blood
Why is the muscle useful in arteries
When they stretch and contract, it helps the look to flow smoothly
Why do veins only need thin walls
There is low pressure
Give an adaptation of veins
Contain valves to prevent blood flowing the wrong way
What is another name for red blood cells
Erythrocytes
Roughly how many erythrocytes are there per mm^3 of blood
5,000,00
How many white blood cells are there per mm^3 of blood
7000
How many platelets are there per mm^3 in the blood
250,000
What is dissolved in plasma
Glucose, CO2 and urea
What substance is found in red blood cells
Haemoglobin
What is the role of Haemoglobin
To bind with O2 in the lungs and release it again in the tissues
What colour are Haemoglobin cells with lots of O2
Bright red
Give 2 adaptations for erythrocytes
No nucleus, more space for Haemoglobin
Disc shape with dimple, large SA
Give 2 types of white blood cell
Lymphocytes
Phagocytes
How does a lymphocyte work
It produces antibodies which stick to foreign cells and destroy them
How does a phagocyte work
It surrounds the foreign cell and engulfs them (digests)
What is the use of platelets
To produce substances needed to clot the blood.
What causes a heart attack
Blood stops flowing to muscles in part of the heat and stops the heart pumping properly
What is a defibrillator
A piece of equipment that can restart the heart by putting an electric shock through it
What is the vena cava
A large vein in which blood flows through to the right atrium
Where does the blood from the body enter
The right atrium
Where does blood from the lungs enter
The left atrium
What is the pulmonary vein
A vein that blood flows to the left atrium
When is the blood pushed into the ventricles
When the atriums are full and the muscles contract
What do muscles in the ventricles do
Push blood out of the heart and to the body
What do heart valves do
Stop blood flowing the wrong way
What is the aorta
A blood vessel that carries the blood to the rest of the body
What is the superior vena cava
Brings blood from the upper body
What is the pulmonary artery
Brings blood to the lungs
What is the inferior vena cava
Brings blood from the lower body to the heart
What are tendons
They stop valves turning inside out
Describe the structure of a heart diagram
Right and left flipped
Aorta (bright red) and superior vena cava (dark red) on the top
Next pulmonary artery (dark red)
Pulmonary veins (bright red)
Left (bright red) and right (dark red) atrium
Left (bright red) and right (dark red) ventricle
Inferior vena cava (dark red)
What parts of the heart are coloured dark red
Deoxygenated
What parts of the heart are coloured bright red
Oxygenated
What is the heart rate
The number of heart beats per minute
What is the stroke volume
The volume of blood pushed into the aorta in each beat (litres)
What is the cardiac output
The volume of blood pushed into the aorta each minute
What’s i the equation for cardiac output
Cardiac output = stroke volume x heart rate
What is cardiac output measured in
Litres/min
Why do fitter people have bigger stroke volumes
Exercise increases strength of heart muscle
What does the body require energy for (3)
Moving, keeping warm, producing and breaking down substances
What is cellular respiration
A series of chemical reactions that release energy from glucose
Is respiration exothermic or endothermic
Exothermic
What is the equation for aerobic respiration
Oxygen + glucose –> carbon dioxide + water
What is glucose taken in by
Small intestines
Where does aerobic respiration occur
In the mitochondria
What is glucose absorbed into
Plasma
What is oxygen carried in
Red blood cells
What happens to the rate of respiration during exercise
It increases
What 2 factors increase aerobic respiration
Faster heart beat
Faster breathing
When does anaerobic respiration happen
When more oxygen is used than replaced
What is the equation for anaerobic respiration
Glucose —> lactic acid
Where does anaerobic respiration occur
In the cytoplasm
Give a benefit of anaerobic respiration
It gives a burst of energy without needing oxygen
Give a negative of anaerobic respiration
Doesn’t give as much energy
Why is heavy breathing required after anaerobic respiration
To replace oxygen, remove lactic acid
Explain the core practical - Respiration rates
Add soda lime to a boiling tube and place cotton wool on top
The soda lime absorbs CO2
Collect some of the small organisms in a weighing boat
Gently shake them out of the container and into the tube
Insert bung and capillary tube, set up a control tube
Place the tubes in a rack in a water bath
Wait 5mins to let organisms adjust to temp
Place coloured liquid in the capillary tube
Mark it’s position, wait 5 mins and measure again
Repeat with different temps
Why do we need cotton wool for the core practical
Soda lime is very corrosive so it is for protection
