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Flashcards in 2 Membrane structure Deck (23):
1

how much of the cell volume do membranes take up?

50%

2

what two primary molecule types do cells have other than lipid attached to their membrane?

proteins and carbohydrates

3

what is the typical composition of protein, lipid and carbohydrate in a cell membrane

<50% lipid
<50% protein
about 5-10% carbohydrate

4

name the types of lipids in the membrane of a cell from most to least abundant

phospholipid
sphingolipid
cholesterol
eicosanoids

5

which leaflet of the plasma membrane is more fluid and why?

-the outer leaflet
-allows lipid rafters to conentrate ligand receptor pairs at specific sites on the membrane for endocytosis

6

what molecule type is PGE2 and what is its function?

-prostaglandin
-induces uterine contraction

7

what molecule type is TXA2 and what is its function?

-thromboxane
-induces platelet aggregation

8

what is the function of leukotienes? name the disease that they are strongly associated with

induce vasodilation and broncoconstriction in ASTHMA / anaphylaxis

9

which type of bond creates a kink in the phospholipid fatty tail and what impact does this have on the membrane? what function can it perform better?

-cis double bond
-makes the membrane more fluid. Also allows for for fusion.

10

What propoerty of cell membranes does HIV take advantage of when infecting its host?

Fusogenic properties of the membrane. can create a multinucleate syncytium

11

what property of membranes does measles take advantage of to infect its host?

fusogenic

12

what is the primary functional difference between sphingolipids and phospholipids?

sphingolipids do not have fusogenic properties. they have saturated fatty chains, making them very rigid

13

Tay Sachs:
-Disease Type?
-Deficiency?
-Accumulating Substance?
-Symptoms?

-Lysosomal storage disease
-hexosaminidase A
-GM2 ganglioside
-mental retardation, blindness, early death

14

Fabrys:
-disease type?
-deficiency?
-accumulating substance?
-symptoms?

-lysosomal storage disease
-alpha-galactosidase A
-ceramide
-kidney failure, skin rash

15

Name 4 factors that effect membrane fluidity and how they effect it.

1. cis double bonds, the more you have, the more fluid the membrane
2. acyl chain length, the shorter the chain, the more fluid
3. temperature, the warmer the environment, the more fluid
4. cholesterol, at body temp, the more cholesterol the less fluid

16

what is the mechanism of infection of mycoplasma (walking) pneumonia?

-feeds on the cholesterol in the cilia of the lung, making the cilia more rigid and unable to clear mucus from the lungs.

17

what membrane components are found in large quantities in lipid rafts?

cholsterol and sphingolipids

18

what are 3 major functions of lipid rafts?

1. signal transduction
2. endocytosis
3. rapid reorginization of the membrane for extracellular matrix modification and motility

19

how many amino acids does it take to span the membrane?

20-25

20

what common characteristic do the amino acids spanning the membrane have?

they are hydrophobic

21

whats a glycoprotein?
what are 3 examples of functions of glycoproteins on the cell mebrane?

a protein with carbohydrate residues residing on it.
1. blood type antigen
2. pathogen recognition sites
3. resevoir for cytokines/growth factors

22

what does the toxoplasma recognize when infecting its host?

a carbohydrate on the outer surface

23

what public health correlate does toxoplasma have?

differrent strains that come from diferent resevoirs infect diferent regions of the GI tract. If you know what region of the gut it attacks, you know the subtype and therefor where it most likely came from