ETHZ/Modeling Basics

From 2007.igem.org

(Difference between revisions)
(Constitutive Protein Production)
(Constitutive Protein Production)
Line 9: Line 9:
The most simple parts in the system are genes that are continuously transcribed to produce a protein. At the same time, proteins have a certain half-life time, which means that they are degraded. This leads to the following simple model of protein production/degradation shown in Fig. 1.
The most simple parts in the system are genes that are continuously transcribed to produce a protein. At the same time, proteins have a certain half-life time, which means that they are degraded. This leads to the following simple model of protein production/degradation shown in Fig. 1.
-
[[Image:basic_fig01.png]]
+
[[Image:basic_fig01.png|thumb|Fig. 1: System of a constitutively produced protein P. Production rate is c<sup>max</sup> and degradation rate is d<sub>P</sub>.]]
To find the concentration of protein P (as a function of time), the system of Fig. 1 can be written as an ODE
To find the concentration of protein P (as a function of time), the system of Fig. 1 can be written as an ODE
Line 19: Line 19:
It is worth looking at the protein production a bit closer. The production of protein P depends on the expression of a gene that codes for this protein. In the case of constant protein production, the gene can be modeled by a ''constitutive promoter'' and a coding region for the protein (Fig. 2).
It is worth looking at the protein production a bit closer. The production of protein P depends on the expression of a gene that codes for this protein. In the case of constant protein production, the gene can be modeled by a ''constitutive promoter'' and a coding region for the protein (Fig. 2).
-
[[Image: basic_fig02.png]]
+
[[Image:basic_fig02.png|thumb|Fig. 2: Model for the gene coding for protein P. The promoter of the gene is continuously expressed.]]

Revision as of 14:41, 7 October 2007

Introduction

The functioning of our model depends mostly on protein concentrations. These proteins are produced within the E. coli cells based on genes that we introduced into the cell. To understand the system, it is crucial to model the gene expression and regulation accurately.

This Wiki page is intended to present the basic mechanisms and assumptions that went into the mathematical description of our iGEM model.

Constitutive Protein Production

The most simple parts in the system are genes that are continuously transcribed to produce a protein. At the same time, proteins have a certain half-life time, which means that they are degraded. This leads to the following simple model of protein production/degradation shown in Fig. 1.

Fig. 1: System of a constitutively produced protein P. Production rate is cmax and degradation rate is dP.

To find the concentration of protein P (as a function of time), the system of Fig. 1 can be written as an ODE

Basic eq01.png

This equation states that the change of protein concentration is a function of protein production (cmax) and protein degradation (dP[P]).

It is worth looking at the protein production a bit closer. The production of protein P depends on the expression of a gene that codes for this protein. In the case of constant protein production, the gene can be modeled by a constitutive promoter and a coding region for the protein (Fig. 2).

Fig. 2: Model for the gene coding for protein P. The promoter of the gene is continuously expressed.