Exchange And Transport In Animals Flashcards
What is blood made up of?
- Plasma (55%)
- White blood cells (<1%)
- Platelets (<1%)
- Red blood cells (45%)
What is plasma?
- The liquid part of blood
- Carries blood cells through blood vessels
- Contains many dissolved substances like carbon dioxide and glucose
What are platelets?
- Fragments of larger cells
- Cause blood clots when a blood vessel has been damaged
- These clots then block wounds and prevent pathogens getting into the blood
NO NUCLEUS
What are two types of white blood cells?
- Phagocytes, flow around pathogens (ingest) and destroy them
- Lymphocytes, produce chemical antibodies which attach to pathogens and destroy them
How are red blood cells adapted to their function?
- Contain the protein haemoglobin which can combine reversibly with oxygen
- No nucleus so more space for haemoglobin
- Small and flexible to can fit through narrow capillaries
- Biconcave shape to maximise surface area for oxygen absorption
- Thin so short distance for oxygen to diffuse through to reach centre of cell
What are the features of an artery?
- Carry blood away from the heart
- Carry oxygenated blood except for the pulmonary artery - Carry blood under high pressure
- Have thick muscular and elastic walls to pump and accommodate blood
- Connective tissue provides strength
- The lumen is narrow
What are the features of a vein?
- Carry blood to the heart
- Carry deoxygenated blood except for the pulmonary vein
- Carry blood under low or negative pressure
- Thin walls, less muscular tissue than arteries
- Less connective tissues than arteries
- Wide lumen
How is a capillary adapted to its function?
Walls are one 1 cell thick, this allows the exchange of molecules between the blood and the body’s cells, molecules can diffuse across this wall
What substances diffuse into cells from capillaries?
- Oxygen, through the capillary wall and into the tissue fluid then the cells
- Glucose, from the blood plasma across the capillary wall and into tissue fluid then the cells
What substances diffuse out of cells into capillaries?
- Carbon dioxide, from cells into the tissue fluid and across capillary walls into blood plasma
- Urea, from liver cells to tissue fluid then across capillary walls into blood plasma
What is the equation for aerobic respiration?
Glucose + Oxygen =
Carbon dioxide + Water (and releases energy)
What are the uses of energy from respiration in animals?
- Metabolic processes, to build larger molecules from smaller ones (e.g. proteins from amino acids)
- To enable muscle contraction
- To maintain steady body temperature of birds and mammals in colder surroundings
- For cell division
- To move molecules against concentration gradients in active transport
- For the transmission of nerve impulses
What is energy from respiration used for in plants?
- To build larger molecules from smaller ones
What is anaerobic respiration?
The incomplete breakdown of glucose to release energy
What is the advantage of anaerobic respiration?
- Releases energy for muscle contraction when the heart abs lungs can’t deliver oxygen fast enough for aerobic
What are the disadvantages of anaerobic respiration?
- Releases much less energy from each glucose molecule than aerobic
- Lactic acid is built up in muscle and blood and must then be broken down after exercise
What is produced during anaerobic respiration in plants and some fungi?
- Ethanol and Carbon dioxide
- This reaction is also called fermentation
Where does anaerobic respiration take place in cells?
Cytoplasm
What is the formula for cardiac output?
Cardiac output =
Stroke volume x Heart rate
Where does aerobic respiration take place?
Mitochondria
Why does heart rate increase during exercise?
- During exercise muscle cells respite faster
- They need more oxygen and glucose and release more carbon dioxide
- Faster heart rate means more blood is pumped around the body so these substances are transported quicker
Where is oxygen exchanged and why?
- Alveoli in lungs
- Needed for respiration
Where is carbon dioxide exchanged and why?
- Alveoli in lungs
- Waste product of metabolism
Where is water exchange and why?
- Nephrons in kidney
- Needed for cells to function properly
Where are dissolved food molecules exchanged and why?
- Small intestine
- Needed for respiration
Where are mineral ions exchanged and why?
- Small intestine
- Needed for cells to function properly
Where is urea exchanged and why?
- Nephrons in kidney
- Waste product of metabolism
How are alveoli adapted for gas exchange?
Small size - small spheres about 300 um in diameter, giving it a larger surface area to volume ratio
Number - there are around 700 million
How is the diffusion path minimised in alveoli?
- The walls of blood capillaries and alveoli are just 1 cell thick
- They are lined with a thin film of moisture, gases dissolve in this, making the path even smaller
How does surface area affect the rate of diffusion?
The larger the surface area, the higher the number of particles that can move in a given time
How does distance affect the rate of diffusion?
If the distance is small, diffusion happens faster because the particles do not have to travel as far
How does concentration difference affect the rate of diffusion?
Diffusion is faster if there is a bigger concentration difference
What is Fick’s law?
Rate of diffusion 🐟
Surface area x Concentration /
Thickness of membrane
How do platelets stop bleeding?
- They have proteins on the surface that enable them to stick to breaks in a blood vessel and clump together
- They secrete proteins that cause a series of chemical reactions to make blood clot
How do antibodies neutralise pathogens?
- They bind to pathogens and damage or destroy them
- They coat pathogens, clumping them together so they are easily ingested by phagocytes
- They bind to the pathogens and release chemical signals to attract more phagocytes
What is the function of the pulmonary artery?
Carries deoxygenated blood from heart (right ventricle) to lungs
What is the function of the vena cava?
Brings deoxygenated blood from body to heart (right atrium)
What is the function of the aorta?
Carries oxygenated blood from heart (left ventricle) to body
What is the function of the pulmonary vein?
Brings oxygenated blood from lungs to heart (left atrium)
What is the process of blood circulation?
- Blood enters through the atria
- The atria contract, forcing blood into the ventricles
- The ventricles contract, into the arteries
- Blood flows through arteries to the organs
- Blood returns to the heart through veins
Do you arteries take blood into or away from the heart?
Away from
Do veins take blood into or away from the heart?
Into
Which ventricle has thicker muscular walls?
Left
Why does the left ventricle have a thick muscular wall?
To create more pressure on the blood as it has to push it around the body
What does the systemic circulation transport?
- Oxygen and nutrients to the body
- Carbon dioxide and other wastes away from cells
What does the pulmonary circulation transport?
- Oxygen from the alveoli into blood
- Carbon dioxide from blood into lungs
What is stroke volume?
The volume of blood pumped out of the left ventricle each time the heart beats
Is respiration endothermic or exothermic?
Exothermic
How do you investigate the rate of respiration? (8)
- Place lime water in a tube then place cotton wool above
- Carefully place a known number of small organisms into the tube then insert the bung and capillary tube
- Set up a control tube
- Place both tubes in a water bath at a set temperature
- Hold a beaker of coloured liquid to the end of the capillary tube so the liquid enters
- Mark the position of liquid in the tube and time for five minutes
- Mark the position of liquid again and measure the distance it travelled
- Repeat the experiment at different temperatures
Why is soda lime used in the respiration experiment?
- To absorb the CO2
- So you can measure the volume of oxygen used
Why is cotton wool used in respiration experiment?
- So organisms don’t come into contact with the soda lime
- Because it is harmful to them
What is the maximum temperature the water bath should be in the respiration experiment and why?
- 50°C
- For ethical reasons as to not harm the organisms
