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19 Cards in this Set
- Front
- Back
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what kinase activity increased in metaphase? |
cyclin dependent kinase went up... cdk1 is mitotic kinase |
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mitoticcdk1/cyclin is a ________ where cdk1 is the ________ and cyclin is the _______ |
heterodimer catalytic subunit (hammer) regulatory subunit which determines specificity of kinase (carpenter) |
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what does cdk1/cyclin do? |
phosphorylate/disassembles the following: pores, lamina, chromosomes (condense), transcription factors(turns off) |
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cdk1/cyclin activates other kinases (servant kinases) to do what? |
break down nuclear envelope and modify microtubule GTPase |
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cdk1/cyclin _______ to lamina tetramers. |
phosphorylates and breaks down into dimers |
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why is it important that there is a mitotic checkpoint? |
because if DNA isn't finished replicating, chromosomes won't separate correctly and both cells will die |
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what completes the Sphase checkpoint? |
KinaseATR senses forks in replication, and keeps cdk1/cyclin OFF |
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how is mitotic cdk1/cyclin kept off? |
the substrate binding site is kept phosphorylated until all DNA has been replicated, then a phosphatase binds to activate it |
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what happens after mitotic cdk1/cyclin activates? |
it enters mitosis and attaches chromosomes |
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what performs spindle checkpoint? |
MAD2 senses unattached kinetochores and blocks enzyme controlling separation (separase) |
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what happens once MAD2 stops blocking separase? |
APC/C causes degradationof cyclin and of the “glue”holding the duplicatedchromosomestogether--> Anaphase occurs |
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what is the third checkpoint? |
DNA damage checkpoint - checks for DNA damage throughout cell cycle |
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all cell cycle length variation occurs in the _____ phase |
G1 |
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which cells are arrested in G2 instead of G0? |
cardiac muscle cells |
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cells need ___________ to enter cell cycle |
growth factor |
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EGF is ___________, its receptor is _________, and it works on ________ cells to cause _______ |
epidermal growth factor her1 a variety of cells cell division |
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PDGF is _________, it's present in ______, it works on _______ to cause _________ |
platelet -derived growth factor blood serum many cell types cause other cells to fill in gaps in a wound |
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what are the differences between cancer cells and normal cells? |
1. don't need growth factors 2. don't need to adhere 3. no well-organized cytoskeleton 4. climb over each other, no crowding worries 5. won't apoptosis (suicide) if something's wrong 6. cells don't go into in senescence, have long telomeres |
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_________ is high in cancer cells to cause long telomeres |
telomerase |
