Researchers are developing a mathematical approach to modeling how cells work that tracks the flow of energy in biochemical networks.
To understand how cells work, scientists have to bring together information from different domains, including chemical, electrical and mechanical. Energy is the common currency of these domains.
The new model allows scientists to bring together and represent the different domains of the cell within the same unifying mathematical description.
It is the creation of a team led by Prof. Peter Gawthrop from the Systems Biology Laboratory at the University of Melbourne in Australia.
The researchers describe the model – and how they applied it to a process that produces energy in muscle cells – in a paper published in the Proceedings of the Royal Society A.
The study appears to be a significant step in systems biology – a field that aims to solve problems about human disease by using computer models to represent the network of biochemical reactions in cells.
The model is based on what is known as the “bond graph approach,” which was originally developed for modeling complex, man-made engineering systems, where energy generation, storage and transmission are fundamental.
The bond graph approach focuses on how power flows from one component of a system to another, and how energy is stored, transmitted or spent within them.
Now, the approach is being used to model biological systems, such as the cells of the human body.
The daily operations that go on in a cell, such as creating and breaking down proteins and other components, are performed by biochemical reactions. These are turned on and off, slowed down and speeded up, according to the cell’s immediate needs and overall functions.
At any given time, the many pathways involved must be monitored and balanced in a coordinated fashion. That is the job of enzymes – to kickstart and control reactions.
Cells contain thousands of different enzymes controlling interlinked networks of biochemical reactions in a hierarchical manner.
The advantage of using the bond graph approach is that it can represent networks of biochemical reactions linked together – by bonds – while obeying the laws of thermodynamics.
It is important to obey the laws of thermodynamics in order to avoid creating a model where some biochemical reactions are generating energy from nothing – like a perpetual motion machine.
Prof. Gawthrop believes scientists and medical researchers are getting more and more interested in how the human body generates, transports and uses energy – both in sickness and in health.
He says the aim of their systems biology lab is to “find out what goes wrong in cells and what happens to cause cellular changes – the very fundamentals of biology.”
In their new paper, he and his colleagues explain how they extended the bond graph approach to allow construction of complex models from simpler components in a hierarchical fashion.
They demonstrate the result by using it to model glycogenolysis in skeletal muscle – the process by which the carbohydrate glycogen in muscle cells is broken down into glucose to provide energy.
Prof. Gawthrop concludes:
“Ultimately we think that our approach will lead to the ability to more easily and reliably modify biological systems with predictable outcomes – so that we can better understand and then treat disease, and ultimately so that we can design new biological systems for biotechnological and biomedical applications.”
In 2012, Medical News Today reported a study where researchers developed a mathematical model that tracked how different forms of dementia spread in the brain neuron by neuron. The team behind the study said it could potentially help to confirm a diagnosis of dementia, and thus enable patients and their families to prepare for future cognitive decline.