BME494s2013 Project Team1: Difference between revisions
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==Background== | ==Background== | ||
[[Image:NLacOperon.jpg|thumb|140px||left|Natural Lac Operon Parts/DNA Schematic]] | [[Image:NLacOperon.jpg|thumb|140px||left|Natural Lac Operon Parts/DNA Schematic [1]]] | ||
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The lac operon itself is a set of genes found in certain bacterias' DNA that is required for the transport and metabolism of lactose. Most commonly found in Escherichia coli, the operon was the first example of a group of genes under the control of an operator region to which a lactose repressor binds. | The lac operon itself is a set of genes found in certain bacterias' DNA that is required for the transport and metabolism of lactose. Most commonly found in Escherichia coli, the operon was the first example of a group of genes under the control of an operator region to which a lactose repressor binds. | ||
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The | The Lac operon functions as a single transcription unit and is comprised of an operator, a promoter, and one or more structural genes such as a regulator or terminator that are transcribed into one polycistronic mRNA. When the bacteria are transferred to lactose-containing medium, allolactose (which forms when lactose is present in the cell) binds to the repressor, inhibits the binding of the repressor to the operator, and allows transcription of mRNA for enzymes involved in lactose metabolism and transport across the membrane. | ||
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<br><br> | The main idea is that E. coli (the most common medium when investigating the Lac operon) conserves its resources by not making Lac proteins when other more easily-accepted sugars, such as glucose, are available [2]. This was tested by Jacques Monod during World War II. He tested the combinations of different sugars for E. coli and discovered that when the bacteria are grown with glucose and lactose, glucose would get metabolized first during the bacteria's growth phase I and then lactose during growth phase II. Thus, when these Lac proteins are made with the presence of lactose, the lac gene and its derivatives can be used to trigger a color change within the cell. Thus, once lactose is used up, glucose acts as the power source, and the lac operon can then act as a reporter gene. | ||
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Revision as of 16:18, 24 April 2013
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Overview & PurposeSarah
Background
Design: Our genetic circuitJulia OUR GENE SWITCH: THE PARTS <tab>pSB1A3-1 is a high copy number plasmid. The replication origin is a pUC19-derived pMB1 (copy number of 100-300 per cell). The terminators bracketing pSB1A3 MCS are designed to prevent transcription from inside the MCS from reading out into the vector.
Building: Assembly SchemeEmily
Testing: Modeling and GFP Imaging
Stakeholder Assessment
Our Team
Works Cited[1] Potts, Michelle. "Microbiology Exam 2." Microbiology Exam 2. N.p., 12 Feb. 2012. Web. 24 Apr. 2013. [2] Muller-Hill, Benno (1996). The lac Operon, a Short History of a Genetic Paradigm. Berlin: Walter de Gruyter. pp. 7–10. ISBN 3-11-014830-7. [3] Full reference.
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