factors affecting membranes

Question 1

what does increased fluidity mean

Answer 1

more permeable

Question 2

what happens when lipids are long/ saturated

Answer 2

-compressed
-high melting point decreases fluidity
-straight unkinked fatty acid means lipid molecules packed more tightly

Question 3

what is affected by short/ unsaturated lipids

Answer 3

-lower melting point increases fluidity
-double bonds in unsaturated fatty acids creates kinks meaning lipid molecules more loosely packed

Question 4

what is affected by higher cholesterol

Answer 4

at body temp higher cholesterol interacts with tails of phospholipids, decreasing fluidity
-at lower temp, prevents membrane from solidifying so maintains fluidity

Question 5

what is affected by lower cholesterol

Answer 5

-at a normal body temp, low level of cholesterol make membrane too fluid, increasing risk of cell bursting

Question 6

how are proteins (embedded and attached to membrane) affected

Answer 6

-at high temp, atoms vibrate breaking hydrogen and ionic bonds that hold their structure together
-tertiary structure changes shape and cannot change back again
-cytoskeleton threads made of protein, if denatures membrane will fall apart, becoming more permeable bc more holes in it

Question 7

what is affected by higher temp

Answer 7

-permeability increases, more kinetic energy and packed loosely, increasing fluidity

Question 8

what is affected by lower temp

Answer 8

-lipids have less kinetic energy, packed more tightly, decreasing fluidity