Factors affecting membrane structure

Question 1

What is the affect of temperature on membrane structure?

Answer 1

increases temperatures means the kinetic energy of the phospholipids will increase

this makes a membrane more fluid and it begins to lose its structure

if temperatures continues to increase the cell will eventually break down

the loss of structure increases permeability

Question 2

What is the affect of temperature on carrier and channel proteins?

Answer 2

proteins will be denatures at high temperatures

as they denature, permeability will be affected

Question 3

What is the effect of solvents on the membrane structure?

Answer 3

water is a polar molecule, creates membrane stability with the phospholipids (particularly the bilayer)

many solvents are less polar than water, e.g. alcohol or non polar benzene

organic solvents will dissolve membrane and disrupt cells

when the membrane is disrupted it becomes more permeable

Question 4

Why is alcohol so damaging and what are its uses?

Answer 4

alcohols dissolve the membranes of bacteria in a wound, which kills them and reduces the risk of infection

pure or strong alcohol solutions are toxic as they destroy cells in the body

Question 5

What are the effects of cholesterol at different temperatures?

Answer 5

at body temp. cholesterol decreases fluidity because it interacts with tails of the phospholipids

at lower temperatures, cholesterol prevents the membrane from solidifying, which maintains fluidity

Question 6

What are the effects of a low cholesterol level?

Answer 6

can make the cell too fluid and more likely to burst