Topic 8 - Exchange And Transport In Animals Flashcards
What is the word equation for aerobic respiration?
Glucose + Oxygen -> Carbon Dioxide + Water
What adaptations of surfaces ensure quick diffusion?
Surfaces are thin so that particles don’t need to diffuse very far.
They have a large surface area so that there is more room for particles to diffuse.
What is the surface area to volume ratio?
Surface Area/Volume
What does a larger surface area mean?
The larger a cells surface area, the more of a substance can diffuse into (and out of) it in a certain time.
Where are Oxygen and Carbon Dioxide exchanged?
In the alveoli
Where and how are Oxygen and Carbon Dioxide exchanged?
By diffusion in the alveoli.
Direction of diffusion
^ - diffusion of Carbon Dioxide.
V - diffusion of Oxygen
Factors that affect the rate of exchange:
Surface area
Diffusion distance
Concentration gradient
How is surface area for exchange maximised in the lungs?
They have millions of alveoli. Each alveolus is closely linked with many capillaries.
Complete the sentence - The _________ the diffusion distance, the faster the rate of exchange.
Shorter
How are the alveolus and capillary adapted to reduce diffusion distance?
The capillary wall and alveolus walls are both one cell thick.
Complete the sentence - the greater the difference in concentration along the path of diffusion, the _______ the rate of diffusion
Faster
How does air being breathed in/out of the lungs help maintain a high concentration gradient?
Air in the alveolus is continually replaced with fresh air that has less carbon dioxide and more oxygen.
How does blood flowing continually through the capillaries help maintain a high concentration gradient?
Blood coming into the lungs has a higher carbon dioxide concentration and lower oxygen concentration than blood leaving the lungs.
Function of red blood cells -
Carries oxygen around the body
Function of white blood cells -
Fight disease
Function of platelets -
Carries substances around the body
Function of plasma -
Helps to clot blood
What do arteries do?
Carry blood away from the heart.
What do veins do?
Carry blood (mostly deoxygenated) back to the heart.
What do capillaries do?
Carry blood through tissues and organs.