Diffusion

Question 1

What is Diffusion?

Answer 1

• The net movement of particles from a region of higher concentration to a region of lower concentration gradient until equilibrium is reached.

Question 2

Is diffusion an active or passive method of transport?

Answer 2

• Passive

Question 3

What does it mean by that diffusion is a passive method of transport?

Answer 3

• It will continue until there is a concentration equilibrium between the two areas.
• Equilibrium means a balance or no difference in concentrations

Question 4

What two ways can molecules diffuse through the plasma membrane?

Answer 4

• Directly through the phospholipid bilayer
• Through channel or carrier proteins by facilitated diffusion

Question 5

What is the hydrophobic core?

Answer 5

• The hydrophobic interior of the membrane. It repels substances with a positive or negative charge (ions), so they cannot easily pass through.

Question 6

What type of molecules can diffuse through the hydrophobic core?

Answer 6

• Small, non-polar molecules diffuse easily between the phospholipids and across the hydrophobic core as they are lipid soluble.
• Large,non-polar molecules e.g. steroid hormones
• small, polar molecules even though they are hydrophilic because they are small.

Question 7

What type of molecules cannot diffuse through the hydrophobic core?

Answer 7

• Large, polar or charged molecules