Thursday, September 20, 2007


Quoted from the Columbia Encyclopedia:
metabolite, organic compound that is a starting material in, an intermediate in, or an end product of metabolism. Starting materials are substances, usually small and of simple structure, absorbed by the organism as food. These include the vitamins and essential amino acids. They can be used to construct more complex molecules, or they can be broken down into simpler ones. Intermediary metabolites are by far the most common; they may be synthesized from other metabolites, perhaps used to make more complex substances, or broken down into simpler compounds, often with the release of chemical energy. For example, glucose, perhaps the single most important metabolite, can be synthesized in a process called gluconeogenesis, can be polymerized to form starch or glycogen, and can be broken down during glycolysis in order to obtain chemical energy. End products of metabolism are the final result of the breakdown of other metabolites and are excreted from the organism without further change; they usually cannot be used to synthesize other metabolites.
The Wikipedia article on Bioinformatics is worth scanning to get a feel for the research area.

Thursday, September 13, 2007

Bioinformatics Reading Thoughts

I'm taking a Bioinformatics class and have been reading "System Modeling in Cellular Biology" by Szallasi et. al. Here are the thoughts that I have had while reading the first few chapters.

Data-driven versus hypothesis-driven research

The world is very complex. Science has been used to understand how things work. Science has often been driven by a hypothesis followed by experimentation which then increases our understanding of the problem --- these questions were based on what we observe or maybe a few researchers have observed. Recently, we continue to gather more and more data which also can be used to drive research --- these questions are based not only on what we might observe in life, but additionally on what the data suggests, in some instances of millions of people. Both ways of attacking the problem can lead us to the same truth, however, it seems that the later has more potential of getting us there quicker.

Modeling is constantly used in biological research. Szallasi mentions a couple reasons why models might be useful (1) testing whether a model is accurate and relect known facts, and (2) models can help us to understand which parts of the system contribute most to some desired properties of interest.

I love how robust and resilient biological processes are. I would love to be able to create a computer program that is a fraction as robust as, say the body is at healing itself.

Many biological processes are modular, much like how good programmers would make a function or class. For example, the human kidney can be substituted into another person and it can work successfully in them. Likewise, in programming, code that connects to a database can be used interchangeably withing multiple programs.

Bottom-up versus Top-down approaches
Bottom-up approaches typically build on existing biological knowledge, whereas, top-down approaches leverage the enormous amount of biological data to find something important to then delve into.