What’s one of the first thing students learn in high school about nucleic acid molecules? It’s that DNA is double stranded and RNA is single stranded. Not only is this fundamentally incorrect, such type of “linear” thinking is, I would argue, a ‘dangerous’ line of thinking, that may be hard for students to escape from.

Any biochemistry student can tell you that, not only can certain types of RNA form secondary and tertiary structures, but that these structures are critical to understanding the catalytic activity of RNA. This has important revelations for evolution (the RNA-first world hypothesis) and for molecular biology.

Microbiology Bytes ran a segment on The shape of HIV RNA (see image below). The higher order, 3 dimensional structure of HIV RNA could play some important role in viral replication and pathogeneiss

This example serves to illustrate the important point that higher order RNA structure could more important in biology than we could have imagined. Therefore, if we keep giving students the impression that RNA (and other molecules) are linear and static, than they could carry with them a false veiw of biological models.

Coincidently, this also is another reason that computational and mathematical modeling in biology will become all important in the coming years. As it turns out, biochemical structures are just too complex to realistically model without computers (at least not easily).

And, as it turns out, even knowing three dimensional structures may not be enough. Carlos Simmerling from Stony Brook University does computational modeling of biomolecular systems (specifically proteins and nucleic acids) as dynamic entities. In other words, intra-interactions, as predicted by mechanics, cause molecules to “move and shake.” These molecular “vibrations” caused by electrostatic interactions could also greatly potentially affect reactivity of molecules in ways we could have never predicted without computer modeling. Simmerling also develops tools to view these molecules in their energetic states. Here’s a video from Simmerling’s group of the enzyme HIV Protease.

These developments stress the need for new scientists (yes, even biologists) to think mathematically and artistically. We need to be aware of all three dimensions (plus the time dimension) in order to work towards building accurate models of biological and biochemical systems.

This entry was posted on Tuesday, April 29th, 2008 at 8:30 pm and is filed under biochemistry, link out, microbiology, musings. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.