Team:Johns Hopkins/Modeling

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==Abstract==
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The expressed purpose of this model is to take the data obtained through experiment and simulate the actions of ''saccharomyces cerevisiae'' at different voltages. The yeasts, in SC complete media, were electroporated at various voltage to induce calcium ion intake through L-type voltage-gated calcium channels. As yeasts have no sarcoplasmic reticulum, calcium will be imported largely from outside the cell. by following precedents set by the Reuter-Stevens (RS) and the Goldman-Hodgkin-Katz (GHK) models, the total charge in calcium imported into the cell during the period of electric stimulation was derived from the current-voltage relationship. The concentration of calcium taken into the cell was derived from the total charge imported, and used to determine the output of yellow fluorescent protein (YFP). the model consists of two major parts: the calculation of calcium intake and the determination of transcription/translation levels induced by calcium. These results fit the data presented in the notebook.
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[[image:Modeling_diagram.jpg|thumb|center|500px|Figure 0. A mathematical model of voltag9e-hated calcium-controlled transcription and expression in S. ''cerevisiae. Note: Degradation constants not shown.]]
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==The Voltage-Gated Calcium Channel==
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===Assumptions===
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*[Ca<sup>2+</sup>]<sub>out</sub> is in excess compared to [Ca<sup>2+</sup>]<sub>in</sub>.
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*The experiment takes place at room temperature (25<sup>o</sup>C).
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*the L-type Ca<sup>2+</sup> (Cch1) channel is homologous to those found in other eukaryotes.
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*Any Ca<sup>2+</sup> that enters into the channel will exit into the cell.
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*The channel is specific and selective for Ca<sup>2+</sup>.
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*The cell is at steady state previous to stimulation.
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*There are two activation gates ('a') and two inactivation gates ('i').
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*Gates of the same type are identical and independent in action.
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*There are approximately 100 calcium channels per yeast cell.
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===Constant Instantiation===
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the overall model of the calcium channel can be subdivided into its constituent gates: the activation gate and the inactivation gate. Collapsed into chemical formulas, the channel's interactions with the calcium can be thought of as such:<br>
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Outside

Revision as of 17:44, 25 October 2010

JHU.

Contents

Abstract

The expressed purpose of this model is to take the data obtained through experiment and simulate the actions of saccharomyces cerevisiae at different voltages. The yeasts, in SC complete media, were electroporated at various voltage to induce calcium ion intake through L-type voltage-gated calcium channels. As yeasts have no sarcoplasmic reticulum, calcium will be imported largely from outside the cell. by following precedents set by the Reuter-Stevens (RS) and the Goldman-Hodgkin-Katz (GHK) models, the total charge in calcium imported into the cell during the period of electric stimulation was derived from the current-voltage relationship. The concentration of calcium taken into the cell was derived from the total charge imported, and used to determine the output of yellow fluorescent protein (YFP). the model consists of two major parts: the calculation of calcium intake and the determination of transcription/translation levels induced by calcium. These results fit the data presented in the notebook.

Figure 0. A mathematical model of voltag9e-hated calcium-controlled transcription and expression in S. cerevisiae. Note: Degradation constants not shown.

The Voltage-Gated Calcium Channel

Assumptions

  • [Ca2+]out is in excess compared to [Ca2+]in.
  • The experiment takes place at room temperature (25oC).
  • the L-type Ca2+ (Cch1) channel is homologous to those found in other eukaryotes.
  • Any Ca2+ that enters into the channel will exit into the cell.
  • The channel is specific and selective for Ca2+.
  • The cell is at steady state previous to stimulation.
  • There are two activation gates ('a') and two inactivation gates ('i').
  • Gates of the same type are identical and independent in action.
  • There are approximately 100 calcium channels per yeast cell.

Constant Instantiation

the overall model of the calcium channel can be subdivided into its constituent gates: the activation gate and the inactivation gate. Collapsed into chemical formulas, the channel's interactions with the calcium can be thought of as such:
Outside