bio - Basic Signal Transduction Review Questions Q1 Using...

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Basic Signal Transduction Review Questions Q1 Using the basic signal transduction diagram Which of the following are true about signalling? (Assume no other factors are present.) If TFa is not phosphorylated, changes in gene expression do not occur. Q2 Which of the following would make signaling permanent? (from class question) TFa binds to and activates a gene that produces a kinase that targets TFa. OR Q2 Which of the following would make signaling permanent? (from class question) TK2 targets TK1 as well as Tfa Q3 Which of the following is could produce a functional, but temporary signal transduction pathway? TFa activates a gene that encodes a phosphatase that targets the receptor OR Q3 Which of the following is could produce a functional, but temporary signal transduction pathway? TK2 activates a phosphatase that targets TK1 Q4 In class we discussed two ways that could make signaling permanent by way of a positive feedback loop, given your understanding of this mechanism, which of the following could also be a mechanism? TFa activates a gene that encodes a protein that inhibits the receptor from being removed from the cell surface. Q5 The self renewal genes are located/found in the nuclei of Differentiated cells This is similar to the question on Friday's quiz. .. all cells have the same genes. .. so even if you were working on genes that are important for characteristics of embryonic stem cells those same genes would still exist in adult stem cells and also in fully mature cells. .. and it might be easier to obtain adult cells in order to get a piece of DNA to work on. ... certainly though if you wanted to look at the function of the gene in a cell you'd want to work on embryonic stem cells. ... however the DNA still exists in ALL cell types regardless of function or age. Q6 You expose some stem cells to the Self Renewal signal, but find that no change in gene expression occurs. You perform an analysis of a stem cells exposed to the signal and obtain the following results: Signal is presentReceptor is present and phosphorylated TK1 is present and phosphorylatedTK2 is present but not phosphorylatedTFa is present but not phosphorylatedGenes are present but not expressed Which of the following could why the signal is bound to the receptor but gene expression is not happening?(pick all that apply) Phosphatase activity This one is the most obvious (but not the only possibility). .. phosphatase remove phosphate groups from proteins, which deactivates them. This data is consistent with a phosphatase acting on TK2 and preventing TK1 from activating TK2. No activation of TK2 means no activation of TFa, and therefore no gene expression. OR Q6 You expose some stem cells to the Self Renewal signal, but find that no change in gene expression occurs. You perform an analysis of a stem cells exposed to the signal and obtain the following results: Signal is presentReceptor is present and phosphorylated TK1 is present and phosphorylatedTK2 is present but not phosphorylatedTFa is present but not phosphorylatedGenes are present but not expressed
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This note was uploaded on 01/25/2010 for the course BIO 101 taught by Professor Houlihan during the Fall '08 term at UMass (Amherst).

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bio - Basic Signal Transduction Review Questions Q1 Using...

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