Topic 3 Mass Transport Flashcards
What does it mean if an organisms has a lager surface area to volume ratio
There is a big surface to exchange substances and smaller distance for them to travel so they can exchange substances a across their surface easily
What does a small SA:V mean
Larger organisms who have a smaller surface area compared to volume and so have a larger distance from the middle to the outside and so will have to have adaptations that allow exchange across surface
What are some adaptations to increase the SA:V
(5)
Villi & microvilli- absorption of digested food
Alveoli & bronchioles - has exchange
Spiritless and tracheoles - insects has exchange
Gill filaments and lamellae - fish gas exchange
Thin wide leaves - plants has exchange
What is respiration
Chemical reaction to release energy in the form of ATP
What is ventilation
Scientific word for breathing
What is gaseous exchange
Diffusion of oxygen from the air in alveoli into the blood and carbon dioxide from the blood into air in the alveoli
What does antagonistic mean
As one muscle relaxes the other contracts
What are the external intercostal muscles
Contract rib cage out and lead to respiration inhalation
What are the internal intercostal muscles
Contraction means that the rib cage moves back leading to exhalation
What happened during inhalation
(6)
- External intercostal muscles contract pulling ribs out
- Internal intercostal muscles are relaxed
- Diaphragm contracts to move down to make space for air
- Air pressure in lungs initially drops as air moves in but rises above atmospheric pressure
- Lung volume increases
- Air moves air moves into lungs as atmospheric pressure is higher than that of the thorax
What is pulmonary ventilation
Total volume of air that is moved into the lungs during one minute (dm3min-1)
What is the equation for pulmonary ventilation
Pulmonary ventilation = tidal volume x ventilation rate
What are alveoli
Tiny air sacks which create a large surface area for gas exchange
What is a property of the alveolar epithelium
Very thin to minimise diffusion distance and surrounded by network of capillaries to remove exchanged gases maintaining a concentration gradient
Give some properties of terrestrial insects
Have exoskeleton made of hard material for protection
Lipid layer to prevent water loss
Insects don’t have lungs they have tracheal System
What are the 3 parts of the insect tracheal system and what do they do
Spiracles - round valve like opening along length of abdomen allows oxygen and carbon dioxide to enter and leave
Trachea network of internal tubes have rings to strengthen the tubes
Tracheoles which branch off of trachea these extent throughout all tissue to deliver oxygen to respiring cells
What are the 3 methods of moving gas in the tracheal system (insects)
- Diffusion use up O2 create Co2 creating concentration gradient from tracheoles to atmosphere
- Mass transport insects contract and relax abdomen to move gases on mass
- When in flight muscle cells respire anaerobically to produce lactate lowering water potential so water moves from tracheoles into cells by osmosis decreasing volume in tracheoles so air is pulled in
Give 3 adaptations of insects for efficient diffusion
- Large number of tracheoles which have a large SA
- Walls of tracheoles are thin and shot distance for diffusion
- Use of oxygen and production of CO2 sets up steep diffusion gradient
H give 3 ways in which insects can prevent water loss
- Small SA:V so less space for water to evaporate from
- Insects have waterproof exoskeleton
- Spiricles can open and close to reduce water loss
Why do fish need a special adaptation for gas exchange
They’re waterproof and have a small SA:V they exchange gas along their gills
Obtain water from oxygen but there is 30 times less oxygen in water
Explain the anatomy of gills for a fish
4 layers of gills on both sides of the head
Gills are made up of fill filaments
Each filament is covered in full lamellae creating a large surface area
When fish open mouth water rushes in and over gills and then out through hole in side of their head
How do gills create a short diffusion distance
Network of capillaries in every lamellae bad very thin gill lamellae
What is the countercurrent flow exchange
When water flows over the gills in the opposite direction to the flow of blood in capillaries so equilibrium is never reached
Explain the internal structure of a leaf
Palisade mesophyll - where photosynthesis occurs
Spongy mesophyll - lots of air spaces
Stomata - where gas diffuses in and out
How does the stomata function
Stomata is open in the day and oxygen can diffuse out and co2 in to reduce water loss stomata closes at night when no photosynthesis will occur
What are xerophytic plants
Plants adapted to survive in environments with limited water
Give 3 adaptations of xerophytic plants to reduce water-loss
- Sunken stomata to trap moisture
- Curled leaves to trap moisture
- Hairs to trap moisture
How are carbohydrates digested
Requires 2 enzymes to hydrolyse them into monosaccharides: amylases and membrane bound disaccharides
Amylase hydrolyses polysaccharides into the disaccharide maltose by hydrolysing the glycosidic bonds
Sucrose and lactase are membrane bound enzymes that hydrolyse sucrose and lactose into monosaccharides
Where is amylase produced
Pancreas and salivary glands
How are proteins digested
Hydrolysed by 3 enzymes
Endopeptidases - hydrolyse peptide bonds between amino acids in the middle of a polymer chain
Exipeptidases - hydrolyse peptide bonds at end of chain
Membrane bound dipeptidases - hydrolyse peptide bonds between 2 amino acids
How are lipids digested
By lipase and the action of bile salts
Lipids hydrolysed ester bond in triglycerides to form monoglycerides and fatty acids
Bile salts emulsify lipids to form micelles (tiny droplets) increasing surface area for lipase to act on
Where is lipase produced
Pancreas
Where are bile salts produced
Liver
What are the 2 stages of digesting lipids
Physical - emulsification
Chemical - lipase
In mammals where does absorption take place after digestion
Ileum
How is the ileum adapted for absorption
Covered in villi increase SA thin walls for short diffusion pathway and surrounded by capillaries to maintain a concentration gradient
What is the role of haemoglobin
Transport oxygen around the body
What is the other type of haemoglobin found in vertebrae
Myoglobin
Where is oxygen loaded?
High partial pressure of oxygen such as the alveoli
Where is oxygen unloaded?
In areas of low partial pressure such as respiring tissues as the need more oxygen for chemical processes
What is the Bohr effect
When a high co2 concentration causes oxyhaemaglobin curve to shift to the right as the affinity for oxygen decreases as co2 changes the shape of haemoglobin slightly
What happens if there is a low partial pressure of co2 in alveoli
Curve shifts left as there is increased affinity for oxygen so unloads more
Give 3 examples of animals who have different types of haemoglobin with different affinities for oxygen
Foetus - myoglobin higher affinity for oxygen
Lamas - high altitudes so huger affinity for oxygen
Worms - underground there is low partial pressure of ixygen so they require a higher affinity
What does a closed circulatory system mean
The blood remains within the blood vessels
What does double circulatory system mean
The blood passes through heart twice in each circuit one circuit delivers to lungs while another delivers to the rest of the body
What are the prefixes for blood vessels in the kidney
Renal
What is the prefix for blood vessels for the lungs
Pulmonary
Which way to arteries carry blood
AWAY from the heart
Which way do veins carry blood
IN to the heart
Give 2 unique properties if cardiac muscle
Myogenic - can contract without stimulation
Never fatigues
Describe how a heart attack would occur
Cardiac muscle is supplied with oxygenated blood these branch off sorts of this becomes blocked the cardiac muscle won’t receive oxygen and won’t be able to respire and so cells will die
Where are the 2 atria located
At the top do the heart
Where are the 2 ventricles located
At the bottom of the heart
What is the acronym for oxygenated blood
L - left
O - oxygenated
R - right
D deoxygenated
Give the properties of the atria chamber
Thinner muscular walls don’t need to contact as hard as they don’t have to pump blood far
Elastic walls to stretch when blood enters
Give the properties of ventricles
Thicker muscular walls to enable bigger contraction
Creates higher blood pressure to enable blood to flow longer distances
What is the role of the right ventricle
Pumps blood to lungs needs to be at a lower pressure to prevent damage to capillaries
So has thinner and more muscular walls compared to left ventricle
What is the role of the left ventricle
Pumps blood to rest of body
Thicker muscular wall as needs larger contractions
What is the role of the vena cava
Carries deoxygenated blood from body into right atrium
What is the role of the pulmonary vein
Carries oxygenated blood from lungs to the left atrium
What is the role of the pulmonary artery
To carry deoxygenated blood away from the right ventricle to words the lungs
What is the role of the aorta
Carries oxygenated blood from left ventricle to rest of body
Where are semi-lunar valves located
In aorta and pulmonary artery
Where are atrioventricular valves found
Between atria and ventricles
What is the function of valves
To prevent the back flow of blood
How do valves function
Only open when the pressure is higher behind the valve
Close when pressure is high in front
What is the function of the septum
Se peered deoxygenated blood and oxygenated blood
Maintains concentration gradient
What are arterioles
Smaller than arteries and connects to capillaries
Give the properties of arteries
(4)
- Thicker muscle layer than veins so that constriction and dilation can occur
- Thicker elastic layer than veins helps maintain blood pressure
- Thicker walls than veins helps prevent bursting
- No valves
Give the properties of veins
(4)
- Thin muscle layer so can’t control blood flow
- Thin elastic layer as lower pressure
- Thin walls as there is little risk of bursts
- Has valves
Give the properties of arterioles
(4)
- Thicker muscle than arteries help restrict blood flow in capillaries
- Thinner elastic layer than arteries
- Thinner walls
- No valves
Give 4 properties of capillaries
- No muscle layer
- No elastic layer
- One cell thick providing short diffusion distance
- No valves
What are the 3 stages of the cardiac cycle
Diastole
Atrial systole
Ventricular systole
What happens in distole
Atria and ventricular muscles relaxed
Blood enters via atria by the vena cava and pulmonary vein
Blood flowing into atria increases pressure
What happens in atrial systole
Atria muscle contract increased pressure caused atrioventricular valves open blood flows into ventricles
Ventricular walls are relaxed
What happened in ventricular systole
AFTER A SHORT DELAY
Ventricular walls contract increase pressure causes atrioventricular valves to close and semi lunar valves to open blood is pushed out of ventricles into arteries
What is the cardiac output
The volume of blood which leaves one ventricle in one minute
What is the equation for the cardiac output
Cardiac output = heart stroke x stoke volume
Stroke volume is the volume of blood that leaves the heart each beat
What is tissue fluid
Fluid containing water, glucose, amino acids, fatty acids, ions and oxygen which bathed the tissue
How is tissue fluid formed
Capillaries have small gals so that liquid and small molecules can be forced out as blood enters capillaries the small diameter results in high hydrostatic pressure so everyhring that forms tissue fluid is forced out this is called ultrafiltration
What remains in the capillary after ultrafiltration
Red blood cells, platelets and large proteins
What happen last to the liquid not re absorbed into the capillary
Absorbed into the lymphatic system which drains into the blood near the heart
What is transpiration
The loss of water vapour from the stomata by evaporation
What 4 factors affect the rate of transportation
- Light - positive correlation more light causes stomata to open so larger surface area for evaporation
- Temperature- positive correlation more heat more kinetic energy more evaporation
- Humidity - negative correlation more water Vapour in the air makes the water potential more positive outside of leaf therefore reducing the water potential gradient
- Wind - positive correlation more wind blows away humid air maintains water potential gradient
What is the cohesion tension theory
Water is a diplomat molecule (o2 is slightly negative hydrogen is positive)
Enables hydrogen bonds to from between different water molecules
Creates cohesion between water molecules as they stick together therefore water travels up xylem as a continuous column
What is adhesion in terms of water
Water sticks to other molecules and adheres to xylem walls
What is root pressure and how is it created
Water moves into roots by osmosis and increases volume of liquid so pressure increase
In 5 steps explain how water moves up the xylem
- Water vapour evaporated out of stomata loss in water creates a lower pressure
- Water lost by transpiration more water pulled up xylem to replace it
- Due to hydrogen bonds between water molecules they are cohesive and create a column of Ayer within the xylem
- Water sticks to the walls of the xylem helping it pull up
- As water is pulled up xylem created tension pulling in to become narrower
What are the 2 cells in the phloem and give some properties of each
Sieve tube elements
Living cells
No nucleus
Contains few organelles
Companion cells
Provide ATP required
Active transport for organic substances
How does sucrose transport from the source to the sieve tube element
- Photosynthesis occurs in chloroplasts creates organic substance (sucrose)
- This creates high conc of sucrose at site if production so ducrise moves down its conc gradient by facilitated diffusion
- Active transport of hydrogen ions occurs from companion cell
- This creates a concentration gradient so hydrogen ions have to move down their conc gradient by Carrier proteins
- Co transport of sucrose with h+ ions occur via protein co transporters to transport sucrose into sieve tube element
How does sucrose move within the phloem
(3)
- Increase of sucrose in sieve tube element lowers water potential
- Water enters sieve tube via surrounding xylem via osmosis
- Increase in water volume in sieve tube increases hydrostatic pressure causing liquid to be forced to word the sink (root)
How does sucrose transport to the sink
(4)
- Sucrose used in respiration at sink or stored as insolvable starch
- More sucrose is actively translated into sink cell which causes water potential to decrease
- Results in osmosis from sieve tube element into sink cell
- Removal of water decreases volume in sieve tube and so hydrostatic pressure decreases
What are the 2 tests for investigating translocation
Tracers & ringing
What is the tracers experiment
Radioactively labelling carbon and plants provided with only this co2 over time this is used in photosynthesis
Thin silk iced from stems are then cut and placed on x ray film that turns black when exposed it radioactive material
So section with sugars would turn black showing the sugars transported in the phloem
What is the ringing experiment
Ring of barn and phloem peeled and removed from tree
By removing phloem trunk swells above removed section analysis of liquid in this swelling showed that it contains sugar
So it shows that if phloem is removed the sugar cannot be transported
