ConstantAmount
Specify variable or constant species amount
Description
The ConstantAmount
property indicates whether
the quantity of the species object can vary during the simulation. ConstantAmount
can
be either true
or false
. If ConstantAmount
is true
,
the quantity of the species cannot vary during the simulation. By
default, ConstantAmount
is false
and
the quantity of the species can vary during the simulation. If ConstantAmount
is false
,
the quantity of the species can be determined by reactions and rules.
The property ConstantAmount
is for species
objects; the property ConstantValue
is for parameter
objects.
Note
When you want the species to participate in a reaction, but
do not want any reactions to modify its quantity, set its BoundaryCondition
to true
,
and ConstantAmount
to false
.
More Information
The following is an example of modeling species as constant amounts:
Modeling the role of nucleotides (GTP, ATP, cAMP) and cofactors (Ca++, NAD+, coenzyme A). Consider the role of GTP in the activation of Ras by receptor tyrosine kinases.
Ras-GDP + GTP -> Ras-GTP + GDP
true
. In
addition, you can set the BoundaryCondition
of
these species to true
, thus making them boundary
species.Characteristics
Applies to | Object: species |
Data type | boolean |
Data values | true or false . The default
value is false . |
Access | Read/write |
Examples
Create a model object named
my_model
.modelObj = sbiomodel ('my_model');
Add a species object and verify that the
ConstantAmount
property setting is'false'
or0
.speciesObj = addspecies (modelObj, 'glucose'); get (speciesObj, 'ConstantAmount')
MATLAB® returns:
ans = 0
Set the constant amount to
'true'
and verify.set (speciesObj, 'ConstantAmount', true); get (speciesObj, 'ConstantAmount')
MATLAB returns:
ans = 1