SB8-Exchange and transport in animals Flashcards
How do many substances move into and out of parts of the body?
Diffusion
What is needed for aerobic respiration?
Oxygen and glucose
What adaptations do the surfaces that substances move through have?
Thin- so particles don’t need to diffuse very far
Large surface are-so there is more room for particles to diffuse
What transport system do humans use to transport substances to and from all cells?
The circulatory system- a fine network of capillaries use blood to do this
How many cells thick are capillaries?
One cell thick
How do you work out the surface area:volume ratio?
Surface area/volume
What do lungs have millions of?
Alveoli
What do alveoli do?
Increase the surface area, increase the speed and increase the amount of gas exchange
What is the formula for concentration?
Concentration = mass of solute (g) / volume of solution (dm3)
What is the formula for the rate of diffusion?
(Surface area x concentration difference) / thickness of membrane
What is the path of blood entering and then leaving the heart?
Veins carry blood back to the heart
A
V
A
What do valves do?
Prevent blood flowing the wrong way
How does blood from the heart and the lungs travel through the heart?
Blood from most of the body enters through the vena cava to the right atrium
Blood from the lungs enters the left atrium through the pulmonary vein
When these chambers are full, the muscles around them contract, pushing the blood into the ventricles
Muscles in the ventricle walls then contract, forcing blood out the heart
Muscles in the atria walls relax and the chambers refill with blood
What is a heart rate and what is it measured in?
The number of times the heart beats a minute (beats/min)
What is a heart attack?
When blood stops flowing to muscles in part of the heart, damaging them and preventing the heart from pumping properly
What is the stroke volume and what is it measured in?
The volume of blood pushed into the aorta in each beat (litres)
What is the cardiac output and what is it measured in?
The volume of blood pushed into the aorta every minute (litres/min)
What is the formula for cardiac output?
Cardiac output(litres/min) = stroke volume (litres/beat) x heart rate (beats/min)
What does regular exercise do to the heart?
It increases the strength of heart muscles and ventricle size
This means fitter people have bigger stroke volumes and their hearts can beat more slowly to achieve same cardiac output as less a fit person
What is cellular respiration?
A series of chemical reactions which release energy from glucose
Is respiration endothermic or exothermic and why?
Exothermic as some energy is transferred out of cells by heating
What is the formula of aerobic respiration?
Glucose + oxygen ~> carbon dioxide + water
Where does aerobic respiration take place?
Mitochondria of cells
What happens during exercise?
Muscles need more energy
Rate of aerobic respiration increases
Muscles cells take more oxygen and glucose from the blood
Heart beats faster to get more blood to muscle cells
Breath faster and deeper to increase amount of oxygen diffusing into the blood in lungs and excrete more carbon dioxide
What is the equation of anaerobic respiration?
Glucose ~> lactic acid
Why does very strenuous exercise result in a significant increase in anaerobic respiration?
Oxygen is used up faster than it is replaces. Anaerobic respiration does not require oxygen and produces lactic acid.
What are the negatives of anaerobic respiration over aerobic respiration?
Aerobic respiration releases more energy from glucose
Anaerobic respiration causes muscles to tire quickly
What are the positives of anaerobic respiration over aerobic respiration?
Can release bursts of energy without needing a sudden increase in oxygen supply
Why can heart and breathing rates remain high after exercise?
Extra oxygen is needed to replace the oxygen lost from blood and muscles
Extra oxygen is also needed to release extra energy required to get rid of lactic acid
What effect does temperature have on respiration?
The higher the temperature the higher the rate of respiration
