SB8a Efficient transport and Exchange

Question 1

Name the three ways substances transport.

Answer 1

Diffusion
Osmosis
Active transport

Question 2

What is Diffusion?

Answer 2

Diffusion is the passive movement of particles down a concentration
gradient (from an area of high to low concentration) until equilibrium

Question 3

What is Osmosis?

Answer 3

Osmosis is the passive movement of water through a semi-permeable
membrane from an area of low solute concentration to an area of high
solute concentration until equilibrium.

Question 4

What is Active transport?

Answer 4

Active transport is the movement of particles from an area of low to high
concentration (against a concentration gradient) using energy.

Question 5

How are Blood vessels adapted to increase the rate of diffusion?

Answer 5

 Thin membranes– so that the particles do not have to diffusion very
far and the diffusion distance is short.

 Have a large surface area – so that more particles can move in and
out at the same time (there is more room for particles to diffuse).

 Have an excellent blood supply – to carry the substances away so
that the difference in concentration is maintained.