70. membrane transport

Question 1

what are the 2 properties that influence whether a particle can permeate the PM without assistance

Answer 1

solubility of the particle in lipid
size of particle

Question 2

name the 2 types of transport

Answer 2

passive and active

Question 3

Molecules and ions that can permeate the membrane are passively driven across by two forces- name them

Answer 3

Diffusion down a
1. concentration gradient
2. electrical gradient

Question 4

name the 3 passive transport mechanisms

Answer 4

osmosis - diffusion of water
ion channels - electrical gradient
simple diffusion - conc. gradient

Question 5

what is the Law of diffusion

Answer 5

Fick’s Law of diffusion

Question 6

Several factors in addition to concentration gradient influence the rate of net of diffusion across the membrane. what are they

Answer 6

1. The magnitude of the concentration gradient
   
   2. The surface area of the membrane across which diffusion is taking place
   3. The lipid solubility of the substance
   4. The molecular weight of the substance
   5. The distance through which diffusion must take place

Question 7

water channel proteins are called…?

Answer 7

aquaporins

Question 8

what is Osmolarity

Answer 8

Osmolarity is the concentration of osmotically active particles present in a solution

Question 9

what is tonicity

Answer 9

the effect a solution ha son cell volume

Question 10

Lower solute concentration, so net movement of water into the cell

Answer 10

Hypotonic

Question 11

Hypotonic

Answer 11

Lower solute concentration, so net movement of water into the cell

Question 12

same solute concentration, so no net water movement

Answer 12

Isotonic

Question 13

Isotonic

Answer 13

same solute concentration, so no net water movement

Question 14

Higher solute concentration, so net movement of water out of the cell

Answer 14

Hypertonic

Question 15

Hypertonic

Answer 15

higher solute concentration, so net movement of water out of the cell

Question 16

what kind of change is isotonic

Answer 16

no change

Question 17

what kind of change is hypotonic

Answer 17

cells swell

Question 18

what kind of change is hypertonic

Answer 18

cells shrink