4.2

Question 1

whats the function of cholesterol in CSM

Answer 1

• regulates fluidity as it reduces sideways movement of phospholipids + other molecules

Question 2

whats the centre of the CSM

Answer 2

HYDROPHOBIC FATTY ACIDS

Question 3

why is there a greater prop of unsaturated fatty acids in CSM

Answer 3

• makes CSM more fluid , C=C bends in hydrocarbon means chains r packed less closely tg so weaker IMF so molecules can change pos more easily = more fluid

Question 4

what does the hydrophobic region prevent

Answer 4

leakage and entering of ions/polar molecules

Question 5

what is the ideal molecule to diffuse straight thru CSM, 3 adj

Answer 5

non polar, small, uncharged

Question 6

what is water potential

Answer 6

tendency of water molecules to move from 1 area to another

Question 7

what is turgor pressure / P, is it pos/neg

Answer 7

as water moves out of cell, hydrostatic P generated as swelling of protoplasm pushes against cell wall - cell contents push against cell wall as a result of water moving in
can be both - pos = pressure eon cell wall
neg = pull on cell wall

Question 8

what is osmotic potential = pi, is it pos/neg

Answer 8

measure of the tendency of water to move from one place to another due to differences in solute concentrations
neg value

Question 9

whats the formula for water potential in animal cells

Answer 9

Ψ = pi
bc no cell wall so no P