Diffusion (TRANSPORT OVER MEMBRANES)

Question 1

what is ‘net movement’

Answer 1

overall movement

Question 2

define simple diffusion

Answer 2

the passive net movement of small, non-polar, lipid soluble molecules, down a concentration gradient from an area of higher concentration to an area of lower concentration directly over the bilayer

Question 3

what factors effect the rate of diffusion

Answer 3

• temperature (molecules gain more KE)
• concentration gradient (steeper=higher rate)
• size of molecules

Question 4

define facilitated diffusion

Answer 4

the passive net movement of polar, charged, hydrophilic, non-lipid soluble molecules, down a concentration gradient from an area of high concentration to an area of low concentration through carrier proteins or a transport channel

Question 5

features of a carrier protein

Answer 5

• binding sights
• two-way
• change shape via collision

Question 6

(rate of diffusion against concentration gradient for polar/non-polar substances graph)

Question 7

Define osmosis

Answer 7

The passive movement of water, by simple diffusion, from a region where it has a higher water potential to a region where it has a lower water potential. Down a water potential gradient through a partially permeable membrane.

Question 8

If concentration of solute increases what happens to water potential

Answer 8

It decreases