An enduring mystery

As you may recall from basic biochemistry courses, introns represent long stretches of noncoding DNA between exons. The latter are the bread and butter of genetic processes because they carry the code that makes us who we are. Introns (junk DNA) may have a functional role in biology, but no one has been able to show it in any rigorous manner. Now there are definitive accounts that suggest that junk DNA has a meaning. In yeast, introns persist after splicing and appear to be associated with cell growth regulation under stress. You can read about this fascinating find in the link below, but I call upon the research community to fix another gap, namely the mysterious fingerprints region in IR spectra. Let me tell you: I am tired of teaching this material on a yearly basis, regurgitating the apparent dissonance between the name “fingerprint” and the lack of any teachable meaning in that region. What a misnomer. When will we get a handle on that paradox and move beyond discussing broad peaks around 3300 cm-1 (an OH stretch) and 1700 cm-1 (a carbonyl stretch)? At least biologists called the regions they had no clue about for their worth. By way of contrast, we chemists have no idea how to interpret 90% of IR, yet we refer to the corresponding regions as “fingerprints.”

https://www.the-scientist.com/news-opinion/a-new-role-for-yeast-introns–helping-cells-cope-under-stress-65330

6 thoughts on “An enduring mystery

  1. I believe it’s called a “fingerprint” region because, in the Bad Old Days, it could be relied upon to look the same in any pure sample of the same material, yet different enough from other compounds; cf. literal human fingerprints.

  2. My distant hazy memories of Org II include the idea that “the Elect” of IR spectroscopy could find patterns and meaning in the fingerprint region, but that those of us who didn’t spend our days immersed in it would have a hard time doing so.

    On a related note, it always amazes me how much useful structural information people were able to extract from IR spectra, in the days before NMR became commonplace.

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