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10 Cards in this Set
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13.compare apoptosis and necrosis |
Both are a form of cell death apoptosis- is plant cell death,cell shrinks,chromosome condensation, DNA fragmentation, blebbs forms on surface Necrosis-cell death due to damage. cell swells and burst releasing components into extracellular space,causes inflammation |
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14.Why is apoptosis needed ? |
Apoptosis is needed to replace lose or damaged cells. from irreparable DNA damage, old cells, cells no longer needed(Tcells), kill cancer, renew tissue |
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15.A.what are caspases? |
Caspases are Cystenic proteases that cleave protiens at the site just C-terminal to Aspartate residue |
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15.B.what are the targets of caspases ? |
-12 different protein kinases including FAK -Lamins(help support nuclear envelope -protein of cyctoskeleton -proten that inhibits capsase activating DNase(CAD) there by activating CAD causing DNA fragmentation |
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16A.what protein comprise the the Bcl-2 family ? |
Bcl-2, Bax,Bak, Bim, Puma, Bad, All share homolgy in up to 4 characterisitc regions cell Bc1-2 homology domians |
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16.B. cell require signals(trophic factors)in order to survive. Describe the process by which a neuron survives in the presence of neurotrophin. |
1.Neurotrophin(trophic factor) binds to trophic factor receptor and starts a signal pathway 2.this results in the phosphorylation of the BH-3 protein Bad 3,Phosphorylated Bad interacts with the 14-3-3 protein preventing it from binding to Bcl-2 4.and Bak is not activated so Cyt c is not released fro mitocondira and caspases are not activated |
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16.C what happens when there is no trophic factor |
1. Bad is not phosphorylated 2.Bad binds to Bcl-2 causing release of Bak or Bax 3.Bak or Bax forms an oligomeric channel in outer membrane of mitocondria 4. causing the release of Cyt-c activating apoptosis |
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17.What is a apoptosome ? |
Apoptosome- when Cyt-c binds to Apaf-1 it casues it to assemble into a apoptosome.which actives pro-caspases by dimerization |
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18.How do the BH3-only proteins Bim and Puma activate apoptosis ? |
they can regulate the activity of Bcl-2 and Bak/Bax, They are activated by environmental stress Puma- induced as parts of DNA damage response system Bim- is usually bound to micotuves, when cell detaches an the cytoskeleton rearranges Bim is relases |
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19.Tnfα and Fas ligand are both examples of death signals. Although they are genrated external to the cell , we concider them molecules of apoptois and not necrosis. why? |
they are concidered to be apoptotic molecues be casue they activat the caspase cascade resulting in cell death. |
