Factors affecting membrane fluidity 2.1.5 (c)

Question 1

what two factors affect membrane fluidity?

Answer 1

temperature
solvents

Question 2

how does an increase in temperature affect membrane fluidity?

Answer 2

increased temperature means greater kinetic energy which means the phospholipids vibrate more

makes the membrane more fluid and thus more permeable

carrier proteins and channel proteins will also denature at high temperatures which will decrease permeability

Question 3

why does membrane permeability increase with an increase in temperature, despite transport proteins being denatured?

Answer 3

the loss of structure in the phospholipid bilayer overpowers this

Question 4

how does water keep the phospholipid bilayer intact?

Answer 4

the hydrophilic phospholipid heads interact with water to keep the bilayer intact

Question 5

what does alcohol do to the cell surface membrane?

Answer 5

causes it to dissolve as they are less polar than water

Question 6

why is alcohol used in anti-septic?

Answer 6

dissolves membranes of bacteria to kill the bacteria

Question 7

why can membrane stability affect the transmission of nerve impulses?

Answer 7

if the membrane of neurones becomes disrupted by temperature or alcohol, the transmission of nerve impulses is also disrupted