Synthesis of trabsmembrane proteins, Golgi complex and vesicular transport, endocytosis, exocytosis Flashcards
what is a SRP composed of
protein and rna
what is SEC 61
secretory pathway
basic definition of cotranslational transport
how soluble proteins get into the endomembrane system
basic definition of synthesis of integral membrane proteins
how transmembrane proteins are integrated into a membrane (except for those in mitochondria and chloroplasts)
describe the three steps of synthesis of integral membrane proteins
1) proteins with signal-anchor sequences are threaded through a channel in the ER membrane until signal-anchor sequence is encountered
2) the ER channel releases the protein into the membrane
3) when translation is complete, the protein remains in the membrane
how do proteins get targeted to mitochondria and chloroplasts
-N-terminus sequences direct proteins to their respective organelles
when proteins get to their directed organelle, what happens next
when the proteins arrive at the organelle, other intrinsic sequences within the protein directs it to the correct compartment or membrane
where are proteins synthesized completely
cytoplasm
describe transport from the er to the Golgi complex
-golgi apparatus receives proteins and lipids from the er and sorts them to other organelle, the plasma membrane, or the cell exterior
which direction does material move between Golgi and er
material moves from the ER to Golgi and then to other compartments and the plasma membrane in proximal to distal direction
describe the structure of the Golgi
-8 or more cisternae stacks
-curved like a shallow bowl
-
describe the polarity of the Golgi complex
cis-medial-trans cisternae
what is the Golgi membrane supported by
actin and spectin
what is the Golgi scaffold linked to
the Golgi scaffold is linked to motor proteins that direct movement of vesicles into and out of the golgi
Cis Golgi network acts as a ______
cis Golgi network acts as a sorting station
what does the cis Golgi network do
the cis Golgi networks sorts whether proteins should continue on to the next Golgi strayer or be shipped back to the er
tras Golgi network ____ proteins into different types of _____
trans Golgi network sorts proteins into different types od vesicles,
what happens to proteins as they’re in the Golgi
proteins are modified “step wise” as they traverse the Golgi
different cisternae of the the Golgi contain different ____ that modify ______
different cisternae of the Golgi contain different enzymes that modify proteins
list the different functions of the Golgi complex
- synthesis of complex polysaccharides
- transport and sorting of proteins
fully processed proteins are ____ to the trans-golgi network and then ___ and ______ to their final destinations
fully processed proteins are exported to the trans Golgi network and then sorted and delivered to their final destination
what is the function of the protein coat on the transport vesicles
1) helps form vesicle structure
2) helps select material on the inside
how do COP1 and Cop2 proteins carry out functions
-they assemble on the cyclic surface of donor compartment membranes at sites where budding takes place
which direction do COP1-coated vesicles travel
they move in retrograde direction (Golgi->er)
which direction do COP2-coated vesicles travel
they move in anterograde direction (er->golgi)
describe vesicular transport
- trafficking vesicles to a compartment
- COP1 proteins help form the transport vesicle
four steps of vesicular transport
1) movement of vesicle
2) tethering vesicle
3) docking vesicle
4) fusion
describe movement of vesicle
- uses cytoskeleton and motor proteins
- COP proteins specify direction of vesicle movement
describe the tethering of a vesicle
tethering vesicle to compartment VIA RABs proteins
describe docking of the vesicle
docking of vesicle to compartment uses SNARE proteins
