SB8 Exchange and Transport in Animals Flashcards
List some substances that need to be transported in and out of the body
0xygen, Carbon Dioxide, Water, Food, Mineral ions
Define urea
a waste product produced from proteins - diffuses from cells to blood plasma for removal by the kidneys
How do you calculate SA:V ratios
1) Find the SA = length x width (for all sides)
2) Find V = length x width x height
3) Divide both sides of the ratio by the volume to get it in the form n:1
Why is a larger SA:V ratio good?
The SA is larger than its volume = large area to diffuse substances into cells
Define SA in affect to the rate of diffusion
The more SA there is available for molecules to move across, the faster they can get from one side to the other
Define conc. gradient in affect to the rate of diffusion
Substances diffuse faster if there’s a big difference in conc. between the area they are diffusing from and to. If there are lots of particles on one side, there are more to move across
Define distance in affect to the rate of diffusion
Substances diffuse more quickly when they haven’t got as far to move
Formula for rate of diffusion
rate of diffusion ~ surface area x conc. difference / thickness of membrane
Define red blood cells (erythrocytes)
- biconcave disc shape = large SA
- no nucleus = more room to carry O2
- haemoglobin binds to O2 to make oxyhaemoglobin
Define phagocytes
Change shape to engulf unwelcome microorganisms - this is called phagocytosis
Define lymphocytes
Produce antibodies against microorganisms and antitoxins to neutralise toxins
Define platelets
Fragments of cells that help blood clot at wounds
List substances in plasma
Red & White blood cells, C02, Urea, Hormones, Proteins, Antibodies, Glucose, Amino acids
Define arteries
- thick walls to help with high pressure
- thick layers of muscle to strengthen them
- elastic fibres allow the to stretch and spring back
Define capillaries
- one cell thick
- permeable walls so substances can diffuse to cell
- narrow so can reach every cell
Define veins
- lower pressure blood
- bigger lumen to help flow
- valves to keep blood flowing in the right direction
Formula for cardiac output
heart rate x stroke volume
Adaptations to the heart
- valves prevent backflow of blood in heart
- left ventricle = thicker wall because it needs more muscle to pump blood to whole body
List 4 heart chambers in order
right atrium, right ventricles, left atrium, left ventricle
List 4 major blood vessels in order
vena cava, pulmonary artery, pulmonary vein, aorta
Describe the flow of blood through the heart
1) Right atrium receives deoxygenated blood from body via the vena cava
2) Deoxygenated blood moves to right ventricle, which pumps it to lungs via the pulmonary artery
3) Left atrium receives oxygenated blood from lungs via the pulmonary vein
4) Oxygenated blood moves to left ventricle, which pumps it to body via aorta
Define respiration
The process of transferring (releasing) energy from the breakdown of organic compounds (glucose)
Aerobic respiration equation
glucose + oxygen –> carbon dioxide + water
Anaerobic respiration equation
glucose –> lactic acid (which builds up in the muscles and causes cramp)
Why is respiration exothermic?
Because energy is transferred to the environment. Some of this energy is transferred by heat
Anaerobic respiration in plants
glucose –> ethanol + carbon dioxide
