Team:Sheffield/Modeling
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The models can be used to predict how the results would change according to changes in parameters and also how the system could be improved. | The models can be used to predict how the results would change according to changes in parameters and also how the system could be improved. | ||
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+ | ===How the model was created=== | ||
The first step in creating the model was to analyse the processes in the system mainly using research literature and the knowledge from the biologists to create the chemical equations for these processes. Next these chemical equations were used to write differential equations for the system, creating a dynamic model. The model was then implemented in matlab to show the changes in the output according to the input and the different parameters in the system. | The first step in creating the model was to analyse the processes in the system mainly using research literature and the knowledge from the biologists to create the chemical equations for these processes. Next these chemical equations were used to write differential equations for the system, creating a dynamic model. The model was then implemented in matlab to show the changes in the output according to the input and the different parameters in the system. | ||
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- | + | ===Main principles in the models=== | |
Both the models are based on the main principles in signal transduction of quorum sensing networks in bacteria and the gene expression. | Both the models are based on the main principles in signal transduction of quorum sensing networks in bacteria and the gene expression. | ||
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- | + | ===Quorum sensing=== | |
Quorum sensing is a mechanism by which bacteria controls their population density, through detection of certain signals emitted from the same species. These signals are in the form of chemicals produced by the bacteria and in vibrio cholerae the quorum sensing signalling molecules are called autoinducers, CAI – 1 and AI-2 . When there is a low cell population density there will be less autoinducers leading towards the production of more cells and at high cell population density there will be more autoinducers and thus inhibiting the production of more cells. | Quorum sensing is a mechanism by which bacteria controls their population density, through detection of certain signals emitted from the same species. These signals are in the form of chemicals produced by the bacteria and in vibrio cholerae the quorum sensing signalling molecules are called autoinducers, CAI – 1 and AI-2 . When there is a low cell population density there will be less autoinducers leading towards the production of more cells and at high cell population density there will be more autoinducers and thus inhibiting the production of more cells. | ||
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The signalling molecules CAI-1 and AI-2 are detected by their cognate receptors CqsS and LuxP/Q respectively. For our biosensor we will be using the CAI-1 and CqsS autoinducer/receptor pair. On detection of the autoinducer a signalling pathway consisting of phosphorelays will be activated which ends in a response regulator protein which acts as a transcription factor. This leads to expression of certain genes. | The signalling molecules CAI-1 and AI-2 are detected by their cognate receptors CqsS and LuxP/Q respectively. For our biosensor we will be using the CAI-1 and CqsS autoinducer/receptor pair. On detection of the autoinducer a signalling pathway consisting of phosphorelays will be activated which ends in a response regulator protein which acts as a transcription factor. This leads to expression of certain genes. | ||
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+ | ===Gene Expression=== | ||
In response to the E. coli detecting CAI-1 which causes it to initiate the phosphorylation cascade to produce certain transcription factors, the E. Coli system tend to use these transcription factors to bind to a reporter DNA to enable it to produce certain proteins upon which the survival of its cells may depend on; thus there is an expression of particular genes which are translated to proteins that enables the E. Coli to perform some specific functions. These specific proteins produced are controlled by the transcription factors which either increases or decreases RNA polymerase binding to the DNA near gene which therefore affects the level of the mRNA transcript produced and hence the production level of these specific proteins. | In response to the E. coli detecting CAI-1 which causes it to initiate the phosphorylation cascade to produce certain transcription factors, the E. Coli system tend to use these transcription factors to bind to a reporter DNA to enable it to produce certain proteins upon which the survival of its cells may depend on; thus there is an expression of particular genes which are translated to proteins that enables the E. Coli to perform some specific functions. These specific proteins produced are controlled by the transcription factors which either increases or decreases RNA polymerase binding to the DNA near gene which therefore affects the level of the mRNA transcript produced and hence the production level of these specific proteins. |
Revision as of 00:39, 25 October 2010