Membranes

Question 1

Total cell volume of membranes?

Answer 1

Usually membranes are 20-25% but it can be up to 100%

Question 2

Chemical composition of membranes

Answer 2

more or less: 50% proteins, 50% lipids and small quantities of carbohydrates

Question 3

Chemical composition of Myelin

Answer 3

Lipids is about 70%.

Question 4

Chemical composition of Mitochondrial inner membrane

Answer 4

Protein is about 80%

Question 5

Lipids are ___________ distributed in the membrane

Answer 5

Lipids are asymmetrically distributed in the membrane

Question 6

Which leaflet is more fluid?

Answer 6

the outer leaflet

Question 7

More membrane fluidity results in?

Answer 7

lipid rafts

Question 8

(4) classes of membrane lipids {order of abundance}

Answer 8

Phospholipids
Sphingolipids
Cholesterol
Eicosanoids

Question 9

_______ are a Tiny but important lipid component of plasma membrane

Answer 9

Eicosanoids

Question 10

Eicosanoid that induces uterine contractions

Answer 10

PGE2

Question 11

Eicosanoid that induces platelet aggregation

Answer 11

TXA2 (tromboxanes)

Question 12

Eicosanoid that induce vasodilation and bronchoconstriction in asthma

Answer 12

LTC4, LTD4, LTE4 (leukotrienes)

Question 13

Phopholipids unique qualities

Answer 13

kinks

Question 14

________ and ________ takes advantage of the fusogenic property of phospholipids

Answer 14

HIV and measles

Question 15

does not have fusogenic properties

Answer 15

Sphingolipids

Question 16

Diseases of Sphingolipid Metabolism

Answer 16

Fabrys, Gauchers and Tay-sachs

Question 17

alteration of sphingolipid properties leads to what type of diseases?

Answer 17

Lysosomal storage diseases

Question 18

do not have fusogenic properties

Answer 18

sphingolipids

Question 19

mental retardation, blindness, early death

Answer 19

tay-sachs

Question 20

hepatenomegaly, mental retardation, long bone degeneration

Answer 20

gauchers

Question 21

kidney failure, skin rash

Answer 21

Fabrys

Question 22

first to be treated successfully with recombinant enzyme replacement therapy

Answer 22

Gaucher and Fabry

Question 23

relatively common in certain ethnic groups who reside on the east coast

Answer 23

ta-sachs

Question 24

lysosomal storage disease

Answer 24

sphingolipids disease

Question 25

gel- like constancy and then apply heat

Answer 25

to get fluid like consistency

Question 26

Factors affecting membrane fluidity (4)

Answer 26

(1) double bonds (2) acyl chain length (3) temperature (heat) (4) cholesterol

Question 27

more double bonds

Answer 27

kinkier and more fluid

Question 28

fewer double bonds

Answer 28

more rigid and less fluid

Question 29

shorter acyl chains

Answer 29

more fluid

Question 30

longer acyl chains

Answer 30

less fluid

Question 31

higher temperature

Answer 31

more fluid

Question 32

lower temperature

Answer 32

mess fluid

Question 33

at body temperature, higher cholesterol

Answer 33

less fluid

Question 34

walking pneumonia

Answer 34

mycoplasma

Question 35

mycoplasma attach to the base of _______ _____ and suck the ________ out

Answer 35

mycoplasma attach to the base of respiratory cilia and suck the cholesterol right out

Question 36

specialized cholesterol and sphingolipid rich microenvironments in the membrane that move rapidly within a leaflet

Answer 36

lipid rafts

Question 37

major functional organizers of the membrane, bringing lipids and proteins together

Answer 37

lipid rafts

Question 38

lipid rafts are critical for (3)

Answer 38

(1) signal transduction (2) endocytosis (3) rapid re-organization of the membrane for extracellular matrix modification and motility

Question 39

great model system for membrane studies

Answer 39

erythrocytes

Question 40

it takes ___-___ aa to span the membrane

Answer 40

20-25

Question 41

nearly all the aa in a membrane-spanning segment are __________

Answer 41

hydrophobic

Question 42

another small but important membrane component

Answer 42

glycoproteins

Question 43

function of carbohydrate at cell surface (3)

Answer 43

(1) blood-type antigen (2) pathogen recognition sites (3) reservoir for cytokines/growth factors

Question 44

toxoplasma gondii

Answer 44

coccidia

Question 45

coccidia recognizes specific carbohydrates on the

Answer 45

Intestinal epithelial cell surface

Question 46

diseases that have intrinsic fusogenicity of membrane lipids

Answer 46

HIV, measles and certain other viral infections

Question 47

disease transmitted via cat feces can cause severe birth defects

Answer 47

toxoplasmosis

Question 48

why is it bad when the cholesterol is sucked from the respiratory cilia?

Answer 48

removing the cholesterol results in a much more fluid membrane that does not permit the cilia to move rhythmically

Question 49

______ cannot be moved out of the respiratory tract and the ________ are thus able to proliferate leading to ______

Answer 49

Mucus cannot be moved out of the respiratory tract and the mycoplasma are thus able to proliferate leading to pneumonia

Question 50

eicosanoid derivatives?(3)

Answer 50

(1) prostaglandins (2) thromboxanes (3) leukotrienes

Question 51

regulation of vascular tone, smooth muscle contractility, and more

Answer 51

prostaglandin

Question 52

platelet aggregation

Answer 52

thromboxanes

Question 53

mediators of asthma and anaphylaxis

Answer 53

leukotrienes

Question 54

the lipid composition of membranes is

Answer 54

asymmetrical

Question 55

true or false: lipid rafts are more fluid than the rest of the membrane

Answer 55

false, more rigid

Question 56

important in bringing together the components of signal transduction pathways, and for mobilizing matrix-modifying enzymes at the leading edge of migrating cells

Answer 56

lipid rafts