Term
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Definition
1. SNAP25
2. syntaxin
3. VAMP |
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Term
| 2 molecules involved in dissociating SNARE proteins to allow vesicle membrane to fuse with the synaptic membrane |
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Definition
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Term
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Definition
| where you start to see budding of membrane back into cytoplasm (endocytosis) |
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Term
| describe the dye experiment used to test vesicle membrane retrieval |
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Definition
| based on the idea that you can take dye (HRP - horseradish peroxidase) & bath synapse in it & if cell gets exocytosis & then the vesicles come back into the membrane, they will pick it up & bring back some of the dye into the cell |
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Term
| describe the capacitance experiment used to test vesicle membrane retrieval |
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Definition
| showed increase in membrane following neurotransmitter release |
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Term
| describe the fluorescent experiment used to test vesicle membrane recycling |
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Definition
| used a fluorescent dye that was pH sensitive (higher pH within physiological normal range of 5 - 8 --> higher fluorescence) & conjugated it to VAMP inside the vesicle |
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Term
| describe the antibody experiment used to test retrieval of vesicle membranes at a frog NMJ |
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Definition
| used an antibody to synaptotagmin that would fluoresce & bathed synapse in it |
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Term
| Endocytosis takes ______ seconds |
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Definition
| 1 - 5 seconds (much slower than exocytosis) |
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Term
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Definition
| vesicles coming back up into neurons |
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Term
| What do you see when you look at budding under a microscope? |
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Definition
| you can see a kind of cloud of dark spots around the membrane |
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Term
| How does clathrin know which membrane specifically to pull in? (vesicle vs original synaptic membrane) |
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Definition
| hones in on protein AP2 which binds to synaptotagmin |
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Term
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Definition
| lattice-work of clathrin molecules pull together to bring in buds of vesicle membrane |
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Term
| Clathrin can't actually pull the membrane out itself...it is dependent on ______ |
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Definition
| dynamin (able to close off the vesicle membrane vs the synaptic membrane) |
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Term
| After labeling dynamin molecules, scientists learned that they are found _______ |
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Definition
| around the neck of the budding vesicles |
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Term
| What is the difference in dynamin activity in the presence of GTP versus GTP-S? |
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Definition
GTP hydrolysis --> separation of vesicle membrane from synaptic membrane
GTP-S --> outcompetes normal GTP & dynamin just keeps building up in a little coil around neck of budding vesicle |
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Term
| mutate dynamin so it isn't working to put membranes back in --> ? |
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Definition
| eventually run out of vesicles |
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Term
| Dynamin is only active when it's ______ |
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Definition
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Term
| Does clathrin remained attached to vesicle membranes when it is brought into the cytoplasm? |
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Definition
| no! clathrin eventually comes apart from the vesicle once it's chilling in the cytoplasm again |
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Term
| Is the clathrin-mediated process a one-way street? |
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Definition
| no! after forming fusion pore, vesicle can seal right up again instead of going through the whole clathrin-mediated process |
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Term
| describe how endosomes relate to vesicle membrane re-uptake |
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Definition
| a whole lot of membrane can fold in together to make a large endosome; endosomes then break down into vesicles (experiments show size of endosomes decreases when number of vesicles increases) |
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