Endo membrane 4/4 and 4/7 Flashcards
o Which proteins will undergo N-glycosylation? Where does this happen?
Ones with w nitrogen atom at an Asparagine (asn) residue. Rough ER
Explain in detail the process of getting proteins to and through the membranes of the
mitochondria, whether fully imported or embedded
- Polypeptide targeted to mitochondrion via targeting sequence at N terminus
- Proteins are recognized by receptors (transmembrane proteins) and brought through outer mito matrix via tom
- Mito matrix proteins brought through tim23 of IMM
- Protein enters matrix, bound to chaperone
- Protein refolds, presequence removed.
o How does the Golgi “know” if proteins are supposed to move into Golgi/further through
the Golgi?
It’ll have proteins that interact with the Golgi complex
- Explain and describe COPI;
return proteins from ERGIC and Golgi complex–>ER. Also transport Golgi enzymes between cisternae in a retrograde direction
Explain and describe COPII;
Anterograde, ER –> ERGIC/Golgi complex.
Explain and describe Clathrin
Forms vesicles to move materials TGN –> endosomes, lysosomes, plant vacuoles. And plasma membrane –>cytoplasmic compartments along the endocytic pathway. They have also been implicated in trafficking from endosomes and lysosomes
o How is direction between endomembrane organelles determined?
It depends on the composition of the membranes and vesicles involved
o What is ERGIC?
Fused transport vesicles and interconnected tubules between ER and golgi complex
o How do vesicles know to travel either cis to trans or vice versa around the Golgi?
It depends on what receptors the membrane is coated with
o How are SNARE proteins involved?
* Describe and outline the steps involved and the differences between the various forms of endo-
and exocytosis
- Synaptic and pre synaptic membranes approach each other
- T/V snare molecules interact to make 4 strand alpha helix bundles
- Alpha helices zip together, pulling bilayers together.
o How does receptor-mediated endocytosis differ from autophagy, pinocytosis,
phagosome assembly, etc.?
Substances that become bound to receptors that collect in specialized domains of the plasma membrane, known as coated pits. It’s specific to one molecule
Which proteins undergo O glycolysation? Where
Ones with an oxygen atom at a _______ in the cytoplasm
o Who/what are TOM and TIM?
* Describe the structure and list the functions of the Golgi apparatus
TOM- Binds to mitochondrial proteins via receptors, brings unfolded proteins in through protein lined channels
TIM-
