Chemistry

A video posted on A Blog Around the Clock a few days ago discusses the mechanisms behind hydrogen bonding. The first half of the video is visually basic -- simple diagrams to illustrate the points in the narrator's lesson -- and includes things like different colors for different atoms, and star shapes that appear where a bond forms.

McGill chemists using a technique known as photoacoustic infrared spectroscopy say they can  identify the composition of pigments used in art decades or even centuries old.

Pigments give artist's materials color and they emit sounds when light is shone on them, and Fourier-transform photoacoustic infrared spectroscopy is based on Alexander Graham Bell's 1880 discovery that showed solids could emit sounds when exposed to sunlight, infrared radiation or ultraviolet radiation.

More recent advances in mathematics and computers have enabled chemists to apply the phenomenon to various materials.

One month to go before the Physics Department closes!  And I have the job of classifying and disposing of unwanted and waste chemicals.  This year, when “everything must go”, this is proving a mammoth task.

How did I get this job?  Being the only practicing chemist in the department, in effect I am Snape, the Potions Master.  This in not only because of my academic training, but my work has taught me what chemical can go with which without creating an explosion (for example, NOT acetone and chloroform!)
A completely man-made chemical enzyme has successfully neutralized a toxin found naturally in fruits and vegetables.   Dr. Jeannette Bjerre at the University of Copenhagen showed how a novel 'chemzyme' was able to decompose glycoside esculin, a toxin found in horse-chestnuts.

Chemzymes are designed molecules emulating the targeting and efficiency of naturally occurring enzymes.  
Most people know enzymes as an ingredient in detergents but in our bodies enzymes are in charge of decomposing everything we eat, so that our bodies can absorb the nutrients. They also decompose ingested toxins, ensuring that our bodies survive the encounter.
A few days ago, while talking about mundane business issues, I learned that today, August 19th, was the birthday of that famous childhood delight, the 'black cow', what would later be called a root beer float.

If you are not up on your carbonated beverage lore, root beer hails from the root of the sassafras tree or the sarsaparilla vine.  When the root mixture is mixed with water, sugar and yeast, it is sweetened and the yeast generates carbon dioxide and carbonates the water.
I expect most of you have heard this song, with its sad words.  It’s full of letters sad and blue, a photograph or two, roses, tokens ….

Not for me!  But as I am clearing out our chemical store, with materials being sent off for disposal prior to the closure of the Reading University Physics Department, some of those bottles do hold memories for me.

There, in an outside brick shed, far enough away to store large quantities of flammable chemicals, sits a jar of sodium nitrite.  But the use to which it was put was somewhat unorthodox. 
If you drink bottled water, soda (or pop, depending on whether you are from Philadelphia or Pittsburgh), or a micro brew-beer in Dallas, Denver or numerous other American cities, you may be carrying an 'iso-signature',  a natural chemical imprint related to that geographic location.

Iso-signatures are a chemical in imprint in hair due to beverages may and could be used to track your travels over time, a new study suggests in the Journal of Agricultural and Food Chemistry.
Researchers at the University of Leeds have found that a compound known as pyrophosphite may have been an important energy source for primitive lifeforms.

The findings, published in the journal Chemical Communications, are the first to suggest that pyrophosphite may have been relevant in the shift from basic chemistry to complex biology when life on earth began. Since completing this research, the authors have found even further evidence for the importance of this molecule and plan to further investigate its role in abiogenesis - how life on Earth emerged from inanimate matter billions of years ago.
By analyzing tiny variations in the isotopic composition of silver in meteorites and Earth rocks, scientists are putting together a timetable of how our planet was assembled 4.5 billion years ago. The new study, published in Science, indicates that water and other key volatiles may have been present in at least some of Earth's original building blocks, rather than acquired later from comets, as some scientists have suggested.

Compared to the Solar System as a whole, Earth is depleted in volatile elements, such as hydrogen, carbon, and nitrogen, which likely never condensed on planets formed in the inner, hotter, part of the Solar System. Earth is also depleted in moderately volatile elements, such as silver.
Two new studies conducted by scientists at Emory University have found that simple peptides can organize into bi-layer membranes. The finding suggests a "missing link" between the pre-biotic Earth's chemical inventory and the organizational scaffolding essential to life.

"We've shown that peptides can form the kind of membranes needed to create long-range order," says chemistry graduate student Seth Childers. "What's also interesting is that these peptide membranes may have the potential to function in a complex way, like a protein."

The results were recently published in Angwandte Chemie.


Photo Credit: Emory University)