BIS104 Edwards SSI06 FINAL - Page 5

BIS104 Edwards SSI06 FINAL - Page 5 - a) p21 protein b)...

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7. When a cell has experienced damage to its DNA, the ATM sensor molecule activates the p53 protein. Describe the sequence of events that is triggered by this activation of p53. To answer this question, use a labeled flow chart that names the important molecules and connects them to each other in the proper reaction sequence. If you can’t recall the exact name of a particular molecule, then indicate its position and role by giving its function (e.g., “a transcription factor”). (8 pts) ATM detects DNA damage ATM activates chck2 Chck2 activates nuclear p53 via phosphorylation so p53 is no longer shuttled to the cytoplasm by MDM2. P53, as a transcription factor, stimulates transcription of mRNA coding for
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Unformatted text preview: a) p21 protein b) Bcl-2 family proteins such as Bad & Bax. p21 binds to and inactivates cdK/cyclin complex at G1 / S to stop cell cycle Bad / Bax proteins interact with surface of mitochondria to trigger leakage of cytochrome c Cytochrome c activates apoptososme complex and initiates caspase hydrolytic cascade. 8. What are caspases, and what is their principle function? (4 pts) DEFINITION: A special family of proteases that are activated during the execution phase of apoptosis. FUNCTION: Cleavage and digestion of specific targets such as nuclear lamins, cytoskeletal proteins, DNA repair enzymes and the activation of DNAses, such as CAD Demo...
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This note was uploaded on 05/31/2010 for the course BIO 1B taught by Professor Carlson,mischel,power during the Spring '07 term at University of California, Berkeley.

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