8) Animal Exchange & Transport Flashcards
What factors affect the rate of diffusion?
Temperature
Concentration gradient
Membrane surface area
What is the surface area to volume ratios for most small organisms?
High surface area to volume ratio
Are multi-celled or single-celled organisms more likely to rely on diffusion?
Single-celled organisms
What would the surface area to volume ratio be for a cube with a volume of 8cm^3 and a surface area of 24cm^2?
3:1
What is Flick’s law?
rate of diffusion = (surface area x concentration difference) / thickness of membrane
What are exchange surfaces?
Surfaces adapted to maximise the efficiency of a gas and solute exchange across them
What adaptations do exchange surfaces have? (4)
Ventilation
Blood supply
Large surface area
Thin membrane
Why does a thin membrane increase rate of diffusion?
Reduced diffusion distance
Why does a large surface area increase rate of diffusion?
More of a substance can diffuse at the same time
Why does a good blood supply increase rate of diffusion?
Blood vessels replenish blood supply to maintain at high concentration gradient
Why does good ventilation increase rate of diffusion?
A high concentration gradient is maintained
How are exchange surfaces ventilated?
Through breathing
What are examples of exchange surfaces?
Small intestine Alveoli Gills Roots Leaves
What do leaves exchange?
Carbon dioxide
Oxygen
What do roots exchange?
Water
Minerals
What do gills exchange?
Oxygen dissolved in water
Carbon dioxide in bloodstream
What do alveoli exchange?
Carbon dioxide
Oxygen
What does the small intestine exchange?
Nutrients from digested food
What fluid is blood made up of?
Plasma
What are tissues?
Groups of similar cells that act together to perform a similar function
What is blood?
A tissue
What are red blood cells also called?
Erythrocytes
What are the two types of white blood cell?
Phagocytes
Lymphocytes
What components are suspended in blood plasma?
White blood cells
Red blood cells
Platelets
What are platelets responsible for?
Blood clotting at wound sites
What are platelets?
Small cell fragments without a nucleus
What are red blood cells responsible for?
Transporting oxygen from the lungs to all body cells
What are white blood cells responsible for?
Defending against infection
How are red blood cells adapated to their function?
Haemoglobin
Small size
Bioconcave shape
No nucleus
Why don’t red blood cells have a nucleus?
To have more room for haemoglobin to maximise oxygen carried
Why do red blood cells have a bioconcave shape?
To increase their surface area
Why do red blood cells have a small size?
To pass through tiny capillaries
What additional sub-cellular structure do white blood cells have compared to red blood cells?
A nucleus
What is strange about white blood cells’ shape?
It can change
Why can white blood cells change their shape?
To squeeze through blood vessel walls into body tissues
To engulf harmful microorganisms
What are the 3 types of blood vessels?
Capillaries
Arteries
Veins
What carries blood around the body?
Blood vessels
What do arteries transport?
Oxygenated blood from the heart to the body
How have arteries adapted to perform their function?
Thick muscle walls
Elastic fibres
Why do artieres have thick muscular walls?
To make them strong and able to cope with the high pressure blood pumped from the heart
What is the only artery that doesn’t carry oxygenated blood?
Pulmonary artery
What do veins transport?
Deoxygenated blood from the organs to the heart
What is the only vein that doesn’t carry deoxygenated blood?
Pulmonary vein
How are veins different to arteries?
Thinner walls due to lower pressure
Wider lumen
Valves
Why do veins have valves?
To prevent the backflow of blood
What do arteries branch into?
Capillaries
When do veins form?
When capillaries join up after passing through the body
What waste product is exchanged in capillaries?
Caron dioxide
What useful products are exchanged in capillaries?
Food
Oxygen
Why do capillaries have very thin walls?
To allow the rate of diffusion to be quicker
What do arteries branch into?
Capillaries
What in the heart acts as a pacemaker?
A group of cells in the right atrium
What are the lower chambers of the heart called?
Ventricles
What are the higher chambers of the heart called?
Atria
How is the left ventricle different to the right ventricle?
Thicker walls as blood is forced out at a high pressure
What are the stages of a heart beat?
1) Blood enters heart via atria
2) Once filled, atria contract and force blood to ventricles
3) When ventricles contract, blood exits the hearts
What are the most important blood vessels?
Aorta
Vena Cava
Pulmonary artery
Plumonary vein
What does the vena cava do?
Supply the heart with deoxygenated blood from the body
What does the pulmonary vein do?
Supply the heart with oxygenated blood from the lungs
What does the aorta do?
Supply the body with oxygenated blood from the heart
What does the pulmonary artery do?
Supply the lungs with deoxygenated blood from the heart
What do the coronary arteries do?
Supply the heart muscle with oxygenated blood
What is cardiac output?
The volume of blood pumped each minute
What is the calculation for cardiac output?
cardiac output = heart rate x stroke volume
What is stroke volume?
The volume of blood pumped out per beat
What is heart rate?
The number of heart beats per minute
What are the 3 key components of the human circulatory system?
Blood vessels
Blood
Heart
Why is the human circulatory system ‘double’?
Blood passes through the heart twice per circuit
What is the human passage of oxygen?
Mouth/nose –> trachea –> bronchi –> bronchioles –> alveoli
Where does gaseous exchange take place?
Alveoli
What surrounds alveoli?
A capillary network
What are alveoli?
Tiny air sacs in the lungs
How are alveoli adapted to be efficient at exchanging substances?
Large surface area
Surrounded by capillaries
What are benefits of capillaries surrounding alveoli?
Rich oxygen supply
Small distance for gases to diffuse
How do oxygen and carbon dioxide move between the air and blood?
Diffusion
What 4 reasons do cells and organisms need energy for?
Construction
Contraction
Homeostasis
Cellular respiration
What cells does respiration happen in?
Every living cell
What is energy used for in construction?
Making larger molecules from smaller molecules
What are proteins made from in plants and animals?
Amino acids
What is joined together to produce starch in plants?
Glucose molecules
What type of reaction is respiration?
Exothermic
What are the 2 types of respiration?
Aerobic
Anaerobic
What is the word equation for anaerobic respiration in animals?
Glucose –> lactic acid
When does anaerboic respiration happen?
When insufficient oxygen reaches the muscles during intense activity
What is the word equation for aerobic respiration?
Glucose + oxygen –> carbon dioxide + water (+ energy)
What is the symbol equation for aerobic respiration?
C6H12O6 + 6O2 –> 6CO2 + 6H2O (+ energy)
Where does aerobic respiration occur?
Mitochondria
What is the word equation for anaerobic respiration in plant and yeast cells?
Glucose –> ethanol + carbon dioxide
What is fermentation?
Anaerobic respiration of yeast cells
What is fermentation of yeast cells used for?
Bread and alcohol production
What happens to glucose during respiration?
Aerobic- fully breaks down
Anaerobic- partially breaks down
What does aerobic respiration produce more of compared to anaerobic respiration?
Energy
ATP
What is a unit of energy?
Adenosine triphosphate (ATP)
What piece of equipment is used to measure respiration rate?
Respirometer
