Lecture 2: Cell Membrane And Membrane Transport

Question 1

2 properties of particles that influence their permeability

Answer 1

-solubility of particle in lipid (charge)
-size of particle

Question 2

4 types of passive transport

Answer 2

-diffusion
-osmosis
-channel mediated
-facilitated diffusion

Question 3

diffusion aka

Answer 3

simple diffusion

Question 4

simple diffusion

Answer 4

movement of solutes across lipid bilayer from high to low concentration

Question 5

osmosis

Answer 5

diffusion of water across membrane

Question 6

channel mediated transport

Answer 6

diffusion through a protein channel (ion channel)

Question 7

facilitated diffusion

Answer 7

carrier mediated diffusion

Question 8

2 types of active transport

Answer 8

-primary
-secondary

Question 9

both types of active transport involve

Answer 9

moving solutes against concentration gradient, requiring energy

Question 10

diffusion depends on what

Answer 10

brownian motion - random thermal motion of molecules

Question 11

what is fick’s law of diffusion: general

Answer 11

-various factors affect diffusion rate
-net rate of diffusion is proportional to concentration gradient

Question 12

what are the factors that affect diffusion rate (5)

Answer 12

-concentration gradient
-surface area of membrane
-lipid solubility
-molecular weight of substance
-distance (thickness) of membrane

Question 13

which factors increase net diffusion rate (3)

Answer 13

-concentration gradient
-surface area of membrane
-lipid solubility

Question 14

which factors decrease net diffusion rate

Answer 14

-molecular weight of substance
-distance/thickness

Question 15

channel mediated transport: gated ion channel

Answer 15

-open in response to stimulus
-allow many ions in at once
-specific to ion

Question 16

the sodium potassium pump is an example of what kind of transport

Answer 16

primary active transport

Question 17

primary vs secondary active transport

Answer 17

-primary: ATP binds to the transporter
-secondary: ATP not directly used

Question 18

what kind of transport is glucose transport

Answer 18

secondary

Question 19

difference between carrier mediated transport and simple diffusion: transport rate v concentration

Answer 19

-transport maximum exists for carrier mediated transport as carriers will become occupied
-simple diffusion is linear, no limit

Question 20

how does water move during osmosis

Answer 20

to area of higher solute concentration

Question 21

higher solute concentration = _________ concentration of water

Answer 21

lower

Question 22

what kind of transport protein is used in the movement of water

Answer 22

aquaporins

Question 23

semi permeable membrane

Answer 23

-membrane is permeable to water but impermeable to solute
-only water moves
-causes increase in volume
-hydrostatic pressure and osmotic pressure are in equilibrium

Question 24

osmolarity/osmolality definition

Answer 24

total concentration of particles per amount of solution

Question 25

is osmolarity of intracellular and extracellular fluids the same or different

Answer 25

same

Question 26

what happens if there is a higher concentration of an impermeable substance inside the cell

Answer 26

water is forced to move and cell volume and shape change

Question 27

tonicity

Answer 27

ultimate effect a solution has on cell volume which determines whether cell size remains the same, swells or shrinks when a solution surrounds the cell

Question 28

effective osmolarity

Answer 28

-osmolarity of non permeable particles in solution
-control actual movement of water

Question 29

Osmolarity vs osmolality

Answer 29

-osmolarity is a volume measure
-osmolality is a mass measure