IGEM:IMPERIAL/2007/Dry Lab/Modelling/ID: Difference between revisions

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==Generalities of the Model==
==Generalities of the Model==
* '''Introduction'''
We can condition the system in various manners, but for the purposes of our project, Infector Detector, we will seek a formulation which is valid for both constructs considered. Our system can thus be modellied by the following Dynamical System:
<br><br>
<math>\frac{d[LuxR]}{dt} = k_1\bigg(\frac{[E]^n}{K_E^n + [E]^n}\bigg) + k_3[A] - k_2[LuxR][AHL]- \delta_{LuxR}[LuxR]</math>
<br>
<math>\frac{d[AHL]}{dt} = k_3[A] - k_2[LuxR][AHL]- \delta_{AHL}[AHL]</math>
<math>\frac{d[A]}{dt} = -k_3[A] + k_2[LuxR][AHL]- k_4[A][P] + k_5[AP]</math>
<math>\frac{d[P]}{dt} = -k_4[A][P] + k_5[P]</math>
<math>\frac{d[AP]}{dt} = k_4[A][P] - k_5[AP]</math>
<math>\frac{d[GFP]}{dt} = k_6[AP]\bigg(\frac{[E]^n}{K_E^n + [E]^n}\bigg) - \delta_{GFP}[GFP]</math>
<math>\frac{d[E]}{dt} = -\alpha_{1}k_1\bigg(\frac{[E]^n}{K_E^n + [E]^n}\bigg) - \alpha_{2}k_6[AP]\bigg(\frac{[E]^n}{K_E^n + [E]^n}\bigg)</math>
<br>
where:<br><br>
[A] represents the concentration of AHL-LuxR complex<br>
[P] represents the concentration of pLux promoters<br>
[AP] represents the concentration of A-Promoter complex<br>
k1, k2, k3, k4, k5, k6 are the rate constants associated with the relevant forward and backward reactions<br>
<math>\alpha_i \ </math> represents the energy consumption due to gene transcription. It is a function of gene length.<br>
n is the positive co-operativity coefficient (Hill-coefficient)<br>
<math>K_E \ </math> the half-saturation coefficient
<br><br>
The system of equations for the two constructs varies strictly with respect to the value of the parameter k1. Construct 1 possesses a non-zero k1 rate constant, whereas for construct 2, a zero value is assumed.


==Simulations==
==Simulations==


===Sensitivity Analysis===
===Sensitivity Analysis===

Revision as of 17:15, 16 October 2007

Model Development for Infector Detector

Formulation of the problem

  • Questions to be answered with the approach
  • Verbal statement of background
  • What does the problem entail?
  • Hypotheses employed

Selection of model structure

  • Present general type of model
  1. is the level of description macro- or microscopic
  2. choice of a deterministic or stochastic (!) approach
  3. use of discrete or continuous variables
  4. choice of steady-state, temporal, or spatio-temporal description
  • determinants for system behaviour? - external influences, internal structure...
  • assign system variables

Our models

Model 1: Steady-state is attained; limitless energy supply

Model 2: Equations developed through steady-state analysis; however due to limited energy supply, we operate in the transient regime

Generalities of the Model

Simulations

Sensitivity Analysis