1.3 Diffusion

Question 1

name the 2 types of diffusion

Answer 1

• simple diffusion(lipid diffusion)
• facilitated diffusion
  [co-transport]

Question 2

Define diffusion

Answer 2

The NET movement of particles from a region of high conc, to a region of lower conc. (Until equilibrium is reached.)

Question 3

what molecules can pass directly through the phospholipid bilayer?

Answer 3

• lipid soluble (steroids)
• very small(water, oxygen, carbon dioxide)

Question 4

what does “passive process” mean

Answer 4

No ATP is required

Question 5

what kind of process is simple diffusion

Answer 5

a passive process

Question 6

what molecules pass via facilitated diffusion

Answer 6

• amino acids
• glucose
  (molecules too big for simple diffusion)

Question 7

how to molecules move via facilitated diffusion

Answer 7

move across the membrane via intrinsic proteins.

Question 8

how do only specific molecules transport via facilitated diffusion

Answer 8

• intrinsic proteins have a specific fit for specific molecules(like enzymes)

Question 9

is facilitated diffusion a passive process?

Answer 9

yes

Question 10

is ATP used up during passive diffusion

Answer 10

No

Question 11

what is the difference between carrier proteins and channel proteins

Answer 11

• carrier proteins have a binding site for a specific molecule
• channel proteins form a water filled pore/channel within the membrane (charged substances can diffuse)

Question 12

what is co-transport

Answer 12

• sodium binds to carrier proteins to allow glucose and amino acids to be transported
• a type of facilitated diffusion which brings MOLECULES AND IONS into cells together on the same carrier protein.

Question 13

what type of transport is significant in absorbing glucose + sodium IONS

Answer 13

sodium-glucose co-transport

Question 14

where are glucose and amino acids transported

Answer 14

the ileum