B2.2 - Diffusion

Question 1

What is diffusion?

Answer 1

This is the net movement of molecules from a region of their higher to their lower concentration down a concentration gradient, as a result of their random movement.

Question 2

What effect does a concentration gradient have on diffusion?

Answer 2

Bigger difference in concentration means faster diffusion rate

Question 3

How do cell membranes work (basic)?

Answer 3

Big molecules can’t fit through the gaps in them but small one’s can (partially permeable)

Question 4

Why does a larger membrane surface area mean a higher diffusion rate?

Answer 4

More particles can pass through at once

Question 5

Particles move about __

Answer 5

Randomly

Question 6

Why do particles spread out (diffusion)?

Answer 6

Because they keep bumping into each other so they get spread out evenly

Question 7

Why does temperature affect the rate of diffusion?

Answer 7

Particles gain energy so they move about faster

Question 8

Give some examples of the substances that move in our bodies by diffusion.

Answer 8

Oxygen, carbon dioxide, urea