Leys- intracellular compartments and protein sorting Flashcards
Proteins that have crossed a membrane are no longer _________ inside the cell.
topologically. must recross membrane to get back into cell
Vesicles move from compartment to compartment within a cell by ________ and __________
budding off and membrane fusion.
Many proteins have signal sequences at their ________ that direct the proteins to cross the membrane. rather than having an ___________
amino terminus, internal signal sequences
The nucleus is surrounded by a __________
a double lipid membrane bilayer
what in nuclear membranes allows molecules, including proteins, to pass from cytosol into the nucleus and back
nuclear pores
. Larger proteins pass through nuclear pores by an
active process
what binds to nuclear transport signals found on some nuclear bound proteins and facilitate transport into the nucleus.
Nuclear import receptors
It generally requires _______ signals to transport proteins from the cytosol into the luman of the mitochondria.
multiple
There are multiple ________ in the mitochondrial membrane. Each _______ interacts with a specific set of proteins.
protein translocators, translocator
Transport of protein into the mitochondria requires what
energy
Proteins enter _______ using a mechanism similar to mitochondrial entry
peroxisomes
Proteins travel from the _________, through the _______ to many sites.
ER, golgi
A ______________ binds to the signal sequence during translation and directs the nascent peptide to the ER membrane.
signal recognition protein (SRP)
Proteins bound for the mitochondria are translated in the ______ and than transported through the mitochondrial membrane. A process that requires _______.
cytosol, ATP.
Proteins that are headed into or through the ER are transported through the ER membrane during translation. This process does not require any
additional energy.
Carbohydrate modification of proteins in the ER helps _____ them to their ultimate location.
direct
The “default pathway” if there are no other signals directing the protein to other locations, is to send the protein to the _______
cell surface.
In _______________ cells store proteins in secretory vesicles until they are signaled to release them from the cell by ______ of the vesicles with the cellular membrane.
regulated secretory pathway, fusion
