Explain how the blood transports oxygen and carbon dioxide in the circulatory system. (5 marks)
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- Red blood cells contain haemoglobin molecules that bind with oxygen in the lungs, which enables efficient oxygen transport.
- Each haemoglobin can carry four oxygen molecules, therefore maximising the blood’s oxygen-carrying capacity.
- Oxygen binds because concentration is high in the lungs and releases where concentration is low in tissues.
- Carbon dioxide is transported through three methods, which ensures efficient waste removal from tissues.
- Most CO₂ converts to bicarbonate ions in blood plasma, as a result of chemical reactions with water.
- Some CO₂ binds to haemoglobin at different sites than oxygen, which allows simultaneous transport of both gases.
- Additionally, some CO₂ dissolves directly in plasma, creating multiple pathways for removal.
- Gas exchange occurs due to concentration gradients between blood and tissues.
- Consequently, oxygen releases from haemoglobin in tissues while CO₂ enters blood, maintaining continuous gas exchange throughout the body.
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- Red blood cells contain haemoglobin molecules that bind with oxygen in the lungs, which enables efficient oxygen transport.
- Each haemoglobin can carry four oxygen molecules, therefore maximising the blood’s oxygen-carrying capacity.
- Oxygen binds because concentration is high in the lungs and releases where concentration is low in tissues.
- Carbon dioxide is transported through three methods, which ensures efficient waste removal from tissues.
- Most CO₂ converts to bicarbonate ions in blood plasma, as a result of chemical reactions with water.
- Some CO₂ binds to haemoglobin at different sites than oxygen, which allows simultaneous transport of both gases.
- Additionally, some CO₂ dissolves directly in plasma, creating multiple pathways for removal.
- Gas exchange occurs due to concentration gradients between blood and tissues.
- Consequently, oxygen releases from haemoglobin in tissues while CO₂ enters blood, maintaining continuous gas exchange throughout the body.