Cell Structure: Simple Diffusion

Question 1

Describe Diffusion.

Answer 1

The passive net movement of particles from a region of higher concentration to a region of lower concentration.

Question 2

What is reached when there is an equal concentration of substance on both sides?

Answer 2

Equilibrium

Question 3

What is there nothing of, after equilibrium is reached?

Answer 3

No concentration gradient in the moment.

Question 4

Is simple diffusion passive or active?

Answer 4

Passive

Question 5

What cannot easily pass through the plasma membrane, and why?

Answer 5

-Charged ions/particles.
-Because the plasma membrane contains a hydrophobic, fatty acid core.

Question 6

What can easily pass through the plasma membrane?

Answer 6

Hydrophobic molecules/uncharged particles.

Question 7

In terms of rate of diffusion, which diffuse faster : small or large particles?

Answer 7

Smaller particles

Question 8

What are the 4 key factors influencing diffusion rate?

Answer 8

-Temperature
-Surface Area
-Distance
-Concentration Gradient steepness

Question 9

How does temperature affect diffusion rates?

Answer 9

The warmer the conditions, the more kinetic energy the particles have, so they move/diffuse faster.

Question 10

How does surface area affect diffusion rates?

Answer 10

Diffusion occurs at a faster rate if the plasma membrane has a larger surface area, as there are more space for molecules to diffuse across.

Question 11

How does distance affect diffusion rates?

Answer 11

The greater the distance, the greater the time it takes for a molecule to pass through.

Question 12

Give 3 examples of molecules which can cross a membrane via simple diffusion.

Answer 12

-Water
-Oxygen
-Carbon Dioxide