lipids and membranes

Question 1

saturated conformation

Answer 1

straight conformation = lowest energy

Question 2

which fatty acids melt at higher temperatures

Answer 2

saturated

Question 3

is there free rotation around a double bonds

Answer 3

no

Question 4

why are triacylglycerols even less soluble in water than fatty acids

Answer 4

no charged carboxylate

Question 5

higher % of long, saturated chains means

Answer 5

higher melting temperature

Question 6

waxes make up

Answer 6

long chain + long chain alcohol

Question 7

glycerophospholipids

Answer 7

two fatty acids and phosphate head and polar head group

Question 8

sphingolipids

Answer 8

sphingosine + fatty acid + head group
also has head group

Question 9

2nd carbon of sphingospine

Answer 9

nitrogen + fatty acid

Question 10

ceramide

Answer 10

sphingolipid

Question 11

what are constituents of membranes

Answer 11

spingolipids + glycerophospholipids + cholesterol

Question 12

what do sterols form

Answer 12

rafts

Question 13

what does sterol influence

Answer 13

Tm (melting temp)

Question 14

micelles

Answer 14

individual units are wedge-shaped

Question 15

vesicle

Answer 15

individual units are culindrical, has bilayer

Question 16

why do bilayers “roll up”

Answer 16

bilayer is unstable unless the edges also have their interactions satisfied so it rolls up

Question 17

cholesterol is _____ specific

Answer 17

animal

Question 18

what composes a large percentage of membrane

Answer 18

protein

Question 19

sterols are highly _____ related molecules

Answer 19

structurally

Question 20

what else are sterols used for

Answer 20

testoterone, estrogen

Question 21

there’s more cholesterol in the _____ membrane

Answer 21

plasma

Question 22

paracrystalline state

Answer 22

frozen like a solid, low temp

Question 23

fluid state

Answer 23

highly fluid, high temp

Question 24

high saturated fatty acids means what abt temp

Answer 24

high temp

Question 25

high unsaturated fatty acids means what abt temp

Answer 25

low temp

Question 26

uncatalyzed lateral diffusion is

Answer 26

very fast

Question 27

moving FA from outter leaflet to inner leaflet (transbilayer diffusion) is very ______

Answer 27

slow

Question 28

why is transbilayer diffusion not favorable

Answer 28

moving hydrophilic head thru hydrophobib tails is unfav

Question 29

flippase requires

Answer 29

ATP

Question 30

scramblase does need ATP

Answer 30

no

Question 31

scramblase which direction

Answer 31

bidirectional

Question 32

flippase which direction

Answer 32

unidirectional

Question 33

flippases keep choline containing lipids in the _______ leaflet

Answer 33

extracellular

Question 34

flippases keep phosphatidylserine in the _______ leaflet. if on other side, could trigger apoptosis

Answer 34

intracellular

Question 35

______ rigidifies and thickent ths bilyaer by forcing nearby phospholipids acyl chains to be more extended

Answer 35

cholesterol

Question 36

lipid rafts contain

Answer 36

cholesterol, sphingolipids

Question 37

rafts are

Answer 37

signalinging centers

Question 38

are glycerophospholipids in rafts

Answer 38

no

Question 39

defining characteristic of lipids

Answer 39

insoluble in water

Question 40

lipid roles

Answer 40

membrane structure energy storage

Question 41

usual number of carbons in common fatty acids

Answer 41

even

Question 42

draw tag

Answer 42

do it

Question 43

draw pl

Answer 43

do it

Question 44

draw FA

Answer 44

do i t

Question 45

why is lauric acid more highe enrgy density than sucorse

Answer 45

energy stored in reduced carbon sucrose more oxidized

Question 46

why are TAGs good energy stores

Answer 46

- higher energy density per gram - no need for hydration

Question 47

why are waxes biological sealent

Answer 47

impervious to water

Question 48

how are micelles formed

Answer 48

detergents

Question 49

example of miclle detergent

Answer 49

SDS

Question 50

what forms vesicles

Answer 50

glycerophospholipids or sphingolipids

Question 51

is there sterol in bacteria

Question 52

more cholesterol in what type of membrane

Answer 52

plasma

Question 53

purpose of flippases and floppases

Answer 53

keep lipids on right side of the leaflet ex: phosphatidylserine on intracellular side

Question 54

what does cholesterol do to the bilayer

Answer 54

rigidifies and thickens

Question 55

without cholesterol, smakll change in temperature can

Answer 55

elicit big change in membrane fluidity

Question 56

with cholesterol, small change in temperature

Answer 56

smaller change in fluiity

Question 57

cholesterol purpose

Answer 57

buffer, temper how fluid the membrane can become