Exchange And Transport In Animals Flashcards
Where does gas exchange happen in mammals
Aveoli
What do aveoli contain
Millions of air sacs where gas exchange happens
What are the alveoli adaptations for efficient gas exhange
moist lining for dissolving gases, good blood supply-maintains concentration gradient of O2 and CO2, very thin walls-minimising distance gases have to move, bug surface area
How easy it is for an organism to exchange substances with the environment depends on…
Its surface area to volume ratio
What does surface area to volume ratio depend on
How large the animal is, the larger the animal the smaller is surface area : volume ratio
Equation for area of surface
Length x width
Equation for volume
Length x width x height
What do red blood cells do
Carry O2 from lungs to all cells in the body
What are red blood cells also known as
Erythrocytes
What features do erythrocytes contain
A biconcave shape-gives it large surface area for absorbing o2, no nucleus-allows more space to carry o2, contains haemoglobin-contains iron,
What do white blood cells do
Defend against infection
What are white blood cells aka
Phagocytes
What is phagocytosis
When phagocytes can change shape to engluf unwelcome microorganisms
What do lymphocytes do
Produce antibodies and antitoxins to fight pathogens and neutralise toxins
What do arteries do
Carry blood away from heart
What do capillaries do
Involved in the exchange of materials at the tissues
What do veins do
Carry blood to the heart
What do platelets do
Help blood to clot
What are platelets
Small fragments of cells that have no nucleus
What is plasma
Liquid that carries everything in the blood
What colour is plasma
Pale straw-coloured
Why are artery walls thick and elastic
Because heart pumps blood out at high pressure
What is the lumen
The hole down the middle of an artery and capillary
Why do arteries contain thick layers of muscle
To make them strong and elastic fibres help them to spring back
Why are capillaries very narrow
So they can squeeze into gaps between cells - means they can carry blood really close to every bodily cell to exchange substances
Why do capillaries have permeable walls
To allow substance to easily diffuse in and out
Why are capillary cells one cell thick
Increases rate of diffusion by decreasing distance over which it occurs
What do capillaries eventually join to form
Veins
Why arent veins thick
Becaus the blood is at low pressure
Why do veins have a bugger lumen than arteries
To helo blood flow
Why do veins have valves
To keep bloodh flowing in the right direction
What does cellular respiration release
Energy
What is respiration
The transfer of energy from the breakdown of organic compounds (usually glucose)
What type of reaction is respiration
Exothermic - releases energy
What is the word equation for respiratiom
Gluose + oxygen — carbon dioxide + water
Symbol equation for respiration
C(6)H(12)O(6) + 6O(2) — 6CO(2) + 6H(2)O
When is anaerobic respiration used
When doing vigorus exercise, body cant supply enough oxygen to muscles for aerobic respiration so muscles start to anerobicakly respire
How does a cramo happen
When glucose is only partially broken down and lactic acid builds up
Word equation for anaerobic respiration
Glucose — lactic acid
Word equation for plants anaerobic respiration
Glucose — ethanol + CO2
What is cardiac output
The total volume of blood pumped by a ventricle every minute
What is stroke volume
Volume of blood pumped by one ventricle each time it contracts
Word equation for cardiac output
Cardiac output (cm(3)min(-1) = Heart rate (beats per min) x stroke volume (cm(3))
What does a double circulatory system mean
Heart pumps blood around body in 2 circuits - heart pumps blood deoxygenated blood to lungs - to take in O2
What type of system do fish have
Single circulatory system - deoxygenated blood from body goes to heart which pumps it round
What are the 4 major chambers of thr heart
Left atrium, right atrium, left ventricle, right ventricle
What are the 4 major blood vessles in the heart
Vena cave, pulmonary artery, aorta, pulmonary veins
What are the steps to how blood is pumped around the body
1) Right atrium recieves deoxygenated blood through the vena cava
2) Deoxygenated blood moves to right ventricle which pumps it to the lungs via the pulmonary artery
3) The left atrium recieves oxygenated blood from the lungs through the pulmonary artery
4) Oxygenated blood moves through to left ventricle which pumps it round the whole body vis the aorta
Why does the left ventricle have a thicker wall and more mucle than the right
To pump blood around the whole body at high pressure
What do you measure the rate of reaction with
A respirometer
What is the rate of reaction
Measuring amount of CO2 consumed by an organism in a given time
What does soda lime do
Absorbs co2 produced
What is cellular respiration
An exothermic reaction which occurs continuously in living cells to release energy for metabolic processes including aerobic and anaerobic respiration
What are the steps to measuring the rate of respiration using wood lice a water bath and a respirometer
1) add some soda lime granules to 2 test tubes
2) a ball of cotton wool is placed above the soda lime in each tube, woodlice are placed above the cotton wool in one tube, glass beads with the same mass as the woodlice are used in the control tube
3) the respirometer is then set up
4) the syringe is used to set the fluid in the manometer to a known level
5) the apparatus is then left for a set period of time in a water bath set the 15°c
6) during this there will be a decrease in the volume of aid in the tube as the woodlice are using the oxygen to respire, this reduces the pressure in the tube causing the coloured liquid in the manometer to move towards the test tube containing the woodlice
7) the distance moved by the liquid in a given time is measured - used to calculate the volume of oxygen taken in by the woodlice per minute - gives u the rate of respiration e.g. cm(3)min(-1)
8) repeat steps 1-7 with water bath at different temps
Why do organisms need to take in oxygen
For aerobic respiration which produces co2 as a waste product
Why does an organism need to take up water
Dissolved food molecules and mineral ions diffuse up along with it
