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Web Exclusives: Systems

Simple Answers
By Alison Davis
Posted October 8, 2007

Question mark iconThis research shows that sometimes you need a model because you simply can't do the experiment in the lab!

Quick, do this math problem: 1,010 x 15,580.

Most of us would run for a calculator—or at least scrap paper and a pencil. Would you believe one answer is 6?

In 15,580 different situations, the bacterium E. coli and its 1,010 genes rely on just 6 basic ways to survive.

Why is this important?

Although human metabolism is more complicated than a microbe's, the two share many basic elements, says bioengineer Bernhard Palsson of the University of California, San Diego. Developing a model to understand the metabolic behavior of bacteria could help scientists predict the behavior of other complex biological systems, like our bodies.

To get started, Palsson and his team created a list of "lab broths" that could meet the basic needs of E. coli. The scientists wrote mathematical formulas to describe how E. coli metabolizes the "soup" nutrients in a variety of environmental conditions. Then, they pieced together 50 years of data on E. coli metabolic reactions. Computers did a lot of the work!

In addition to discovering only six basic behaviors, the researchers learned that E. coli makes its metabolic "decisions" based upon just a few key ingredients. The findings suggest that despite having thousands of working parts, complex systems like E. coli metabolism can still be understood—and that asking questions of very complex systems can result in a "simple answer."

Palsson and others plan to use the same modeling approach to study healthy and diseased human cells.

Learn about related research

This page last reviewed on April 22, 2011