4.2 Diffusion

Question 1

What does the term ‘passive’ mean?

Answer 1

Energy comes from the natural movement of particles.

Question 2

What is diffusion?

Answer 2

The net movement of molecules or ions from a region where they are more highly concentrated to one where their concentration is lower until evenly distributed.

Question 3

What type of process is facilitated diffusion?

Answer 3

Passive

Question 4

What is the difference between simple diffusion and facilitated diffusion?

Answer 4

Facilitated diffusion occurs at specific point on the plasma membrane where there are special protein molecules ( protein channels and carrier proteins).

Question 5

Explain what happens when there is the specific ion present by a protein channel.

Answer 5

The protein channel opens.
The ions bind to the protein causing it to change shape so that it closes to one side of the membrane and opens at the other side of the membrane.

Question 6

Explain what happens when a specific molecule is by a carrier protein.

Answer 6

The molecule binds with the protein.
This causes it to change shape so that the molecule is released to the inside of the membrane.