Gas Exchange (PPT 2-4) [U1/ T2]

Question 1

What are the features of efficient gas exchange?

Answer 1

• Large surface area
• Moist membrane
• Thin and permeable membranes

Question 2

How does the surface area affect gas exchange?

Answer 2

Large surface area = faster diffusion

Question 3

How does moist membrane affect gas exchange?

Answer 3

Gases dissolve in water first to diffuse from one side of the membrane to the other

Question 4

How does a thin and permeable membrane affect gas exchange?

Answer 4

So gas molecules can move through the membrane quickly and efficiently.

Question 5

How if diffusion achieved in animals of a larger size?

Answer 5

Through a specialised gas organ

Question 6

What are 2 basic ways of increasing surface area of a gas exchange organ?

Answer 6

• External expansion of the body surface (ie. gills)

- Internal expansion of the body surface (ie. lungs)

Question 7

How is the structure of the gills related to its function?

Answer 7

• Large SA/V ratio
• Specialised moist exchange surface
• Thin permeable membranes
• Constant water movement to create a favourable concentration gradient.
• Plentiful blood supply in opposing directions maintaining a favourable concentration gradient.

Question 8

How is the structure of the alveoli related to its function?

Answer 8

IDK

Question 9

For diffusion to occur efficiently, what do you need?

Answer 9

• Minimal difussion distance
• Increased surface area
• Permeable thin & moist membranes
• Favourable concentration gradient that stays maintained.

Question 10

What are the 3 ways CO2 is carried within the transport medium?

Answer 10

• 23% combines with Haemoglobin
• 7% is carried in solution
• The remainder passes into red blood cells where it is converted into hydrogen carbonate ions.