Identify all of the true

statements:

A concentration gradient is the difference between

two concentrations

Active transport allows cells to transport molecules

against a concentration gradient

Diffusion results in a net overall movement from a low

concentration to a high concentration

In diffusion particles are moving around randomly in

all directions

Osmosis requires energy from respiration to be carried

out

Partially permeable membranes allow any molecules

to pass through them

a) True. The bigger the difference, the steeper the concentration gradient and the faster the molecules of a substance will diffuse.

b) True. Active transport requires cellular energy to achieve this.

c) False. Diffusion is the net movement of molecules from an area where they are at a higher concentration to areas where they are at a lower concentration.

d) True. For diffusion to work, the particles must be able to move around.

e) True. Osmosis requires energy from respiration to be carried

out.

f) False. Partially permeable membranes allow only water but not other dissolved substances to pass through.