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Tuesday, October 19, 2010

National Chemistry Week

This is National Chemistry Week in the United States of America. Janet Stemwedel reminded us [Holy mole-y, it’s National Chemistry Week!]. She's a chemist AND a philosopher!1

I like chemistry because it helps us understand really important things like biology. Here's the biochemistry version of the Periodic Table of the Elements. It shows you which ones you can ignore!

1. Eat your heart out, John Wilkins.


  1. here's an Earth Scientist's Periodic Table of the Elements and their Ions

  2. Since (say) mercury and lead are so irrelevant, I trust you won't mind if I stir some into your coffee :-)

  3. Really. I would think some of the toxic or radioactive elements would be important to biology and biochemistry at least. Myriad of reasons - dating, fossils, cell damage, etc.

    Then, there are all though elements in the environment if not in cells. Again, these are relevant to Biology - fossils for example.

    I think the chart needs some revision.

  4. I'm pretty satisfied with this, unlike the commenters above.

    The elements not highlighted in colour are so rarely encountered by living cells as to be basically irrelevant to life.

    Fossils are not alive. Radiometric dating is relevant to geology, not living cells (other than the brain cells of some individual humans). Cell damage and DNA damage caused by radionucleotides is really rare outside of some laboratories and very recent industrial areas.

    If you want to understand the chemistry of life, focus on the coloured elements in this table. You'll gain a little, but very little knowledge about life, by studying the chemistry of the other elements.

  5. Pah. Chemistry. Almost physics, really, and there are hundreds of philosophers of physics.

    Now, philosophy of soil science: that's something...

  6. To elaborate on TheBrummell's point, most of the elements highlighted seem to correspond to certain groups: red seems to correspond to elements in organic chemicals; purple seems to correspond to ions that pop up in biochemistry everywhere, e.g. nerve stimulation; dark blue seems to correspond to essential cofactors in a lot of enzymes and proteins; and light blue I'm guessing to be similar to dark blue but are needed in trace amounts.

    I have the textbook and I could verify my guesses, but I think I'm mostly correct.

  7. As to the practice of biochemistry, there are a bunch of chemicals that could be highlighted off the top of my head like lithium, rubidium, and cesium. Anyway after seeing this list, my question is why some elements aren't used in biology, like lithium-- it's everywhere and it's an alkali metal like sodium and potassium. My converse question would be, what the heck are aluminium and gallium doing?

  8. "Chemistry is not physics with less rigor. In chemistry there are discoverable guiding principles for systems which are too complex for a "first principles" approach. The nature of chemistry is very difficult to explain to most physicists, in my experience"
    --William Lipscomb

  9. John S. Wilkins: "Now, philosophy of soil science: that's something..."

    I'm in the middle of a PhD at a Soil Science department. What Philosophy I've seen has been entirely concerned with Agriculture and Agronomy, and Soil Science's relationship to those fields. It's less than thrilling, unless you have a strong fascination with big machines equiped with sharp things front and back.

  10. The table leaves off Tungsten, which is incorrect. And Lithium probably does have a natural role, since it inhibits phosphoinositide phosphatase, and is concentrated in the pituitary.

    We need to banish the word "doesn't" from biochemical textbooks. After all, selenium "didn't have a biological function," not so very long ago.

  11. The red elements (CHNOPS) are the most common elements in living cells. Together they make up 97% of the weight of a cell.

    The purple elements are the five essential ions found in all species. The traces element are blue, the most abundant ones are darker than the ones that are much less abundant.

    I'm only considering elements that are essential for life and are present in large numbers of species.