Flashcards in 3 Membrane Transport Deck (28):
can ions cross the plasma membrane freely?
no, they need a transporter
what types of molecules can cross the PM freely?
hydrophobic, small molecules, O2, CO2, N2, benzene
when a molecule crosses the membrane freely, down its gradient, what is this called?
when something is actively transnported, what is the key distinction between this and other transport?
ATP is being used (up a gradient)
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
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
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)
what is the exchange rate of the Na/K ATPase?
3 Na out for every 2 K in
the CFTR is an example of what type of protein?
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
P glycoprotein is aka what?
MDR complex, it is the transporter
severe HDL deficiency in the plasma is characteristic of what disease?
accumulation of cholesterol ester in various tissues is characteristic of what disease? what does this lead to?
-lymphadenopath, hepatosplenomegaly, peripheral neuropathy, and severe cardiovascular disease
mutations in ABC-1 leads to what?
-this ABC is responsible for the transport of cholesterol out of the cell. without cholesterol, HDL has nothing to pick up
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
phagocytosis is mediated by what filament molecule?
virus particles and smaller particles are taken into the cell by what mechanism?
bacteria and larger macromolecules are taken into the cell by what mechanism?
T/F phagocytosis is receptor mediated?
toxoplasmosis/coccidiosis enters the cell via what mechanism?
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
what is the significance of familial hypocholesterolemia?
LDL receptor mediated endocytosis does not work and cells can not endocytose LDL to get cholesterol
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.
what is the significance of leishmaniasis?
enters the cell via phagocytosis
what is the significance of listeriosis?
what is the significance of TB?
what is the significance of streptococcus?