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Flashcards in 3 Membrane Transport Deck (28):
1

can ions cross the plasma membrane freely?

no, they need a transporter

2

what types of molecules can cross the PM freely?

hydrophobic, small molecules, O2, CO2, N2, benzene

3

when a molecule crosses the membrane freely, down its gradient, what is this called?

simple diffusion

4

when something is actively transnported, what is the key distinction between this and other transport?

ATP is being used (up a gradient)

5

what type of trasnport does the glucose permease use?

facilitated diffusion: there is a confromation change after glucose binds, bringing it into the cell
-this is not coupled

6

how does a symporter work? give a key example

one molecule goes down its gradient, deriving enough energy to push one molecule up its gradient - they are both going in the same direction though
-Na-glucose symporter

7

how does an antiporter work? give an example

-one molecule goes in, the other goes out, one is down its gradient, the other is up
-Band 3 anion antiporter (anion exchanger)

8

what is the exchange rate of the Na/K ATPase?

3 Na out for every 2 K in

9

the CFTR is an example of what type of protein?

ABC transporter

10

what is the signifigance of the MDR complex?

it pumps chemo drugs out of the cell and in cancer cells this can be upregulated, making them harder to treat

11

P glycoprotein is aka what?

MDR complex, it is the transporter

12

severe HDL deficiency in the plasma is characteristic of what disease?

tangiers

13

accumulation of cholesterol ester in various tissues is characteristic of what disease? what does this lead to?

tangiers
-lymphadenopath, hepatosplenomegaly, peripheral neuropathy, and severe cardiovascular disease

14

mutations in ABC-1 leads to what?

tangiers disease
-this ABC is responsible for the transport of cholesterol out of the cell. without cholesterol, HDL has nothing to pick up

15

what is pinocytosis?

the cell sampling bits of the environment by taking in some of the cell membrane and engulfing some of the ECM in the process

16

phagocytosis is mediated by what filament molecule?

actin

17

virus particles and smaller particles are taken into the cell by what mechanism?

endocytosis

18

bacteria and larger macromolecules are taken into the cell by what mechanism?

phagocytosis

19

T/F phagocytosis is receptor mediated?

True

20

toxoplasmosis/coccidiosis enters the cell via what mechanism?

phagocytosis

21

walk through the endocytosis of LDL

-LDL binds to LDL receptor
-receptor and ligand are endocytosed
-uncoating takes place via H pumps
-receptor and ligan fuse with endosome
-LDL is metabolized and cholesterol released into cell
-LDL receptor buds off and is returned to the membrane

22

what is the significance of familial hypocholesterolemia?

LDL receptor mediated endocytosis does not work and cells can not endocytose LDL to get cholesterol

23

what is the significance of influenza and rabies with regard to RME?

the enter the cell via RME, fuse with the endosome, and then their genetic material is released into the cell to be replicated.

24

what is the significance of leishmaniasis?

enters the cell via phagocytosis

25

what is the significance of listeriosis?

phagocytosed

26

what is the significance of TB?

phagocytosed

27

what is the significance of streptococcus?

phagocytosed

28

significance of mesothelioma?

filaments are phagocytosed, inhibiting the cell from dividing properly and leading to malignancies