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Marvelous milk

1 Dec

Cow suckling her calf

Most of my news articles don’t have a back story. But my most recent chemistry story combined food, molecules, animals. . .  and a little bit of family.

Dairy runs in my family. My grandfather ran a small dairy for more than 30 years, in and around his day job. My father has worked in dairy science, as a university professor, but mostly working in Extension, working with dairy farmers and tools that keep track of milk data and production. My uncle, a large animal veterinarian, does embryo transfers in cattle.

So, when an editor approaches me with a milk story, I’m game.

Though I knew that milk provides a way for moms to provide antibodies to babies, I’m intrigued by the possibility that there are a mixture of enzymes that may both activate milk proteins within the stomach and then shield them from being shredded into amino acids. This chemical and biological marvel mixes fats, proteins, and sugars and even whole cells. Researchers now have a pretty good picture of what’s in there, but plenty of work remains to figure out how it all works together.

Image Credit: Wikimedia Commons

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MotW: Nobel Prizes all about the carbon

8 Oct

Carbon is the big star among the science Nobel Prizes this week. Sure, IVF is a big deal, too. But, today, I’m all about the element that ruled my life as an organic chemist. Carbon more than math is the universal common denominator of ‘O-chem. “As my undergraduate professor once quipped , “You just have to be able to count to four: four bonds to carbon.”

 

, from Wikimedia Commons”]But otherwise the two prizes aren’t all that similar. The physics prize for the discovery of graphene— sheets of carbon the thickness of a single atom– recognizes a discovery just a handful of years old. It’s superstrong, transparent, incredibly dense– fascinating properties that have scientists excited about what we might be able to do with it. But what has it done for the world lately? Not much, at least not yet. Some scientists think the award is premature.

The chemistry prize was awarded for classic organic synthesis: using palladium, a matchmaker metal with the remarkable ability to help chemists link together complicated patterns of carbon atoms. Although the enzymes between living cells are gifted at making these types of connections,  stringing carbon atoms together in precise ways  within a flask in a traditional chemistry lab is both art and science (and often an exercise in frustration).

But this is one elegant solution. The scientists discovered the reactions in the 1970s, but the chemistry that had come into its own by the time I started graduate school in the late 1990s.  As a result, my chemist mind thought, “oh, really, they haven’t awarded a Nobel for this yet?” But there’s no question that this science has touched people all over the world.  The pain reliever I took yesterday (Naproxen, the active compound in Aleve), cancer drugs, plastics,  compounds in TVs and other displays and flexible screens all result from chemists using these techniques on an industrial scale.

 

Naproxen structure via Wikimedia Commons

 

Seaweed, sushi and science

17 Dec
Sushi!

iStockphoto/ShyMan

I prefer my seaweed applewood smoked. However, truthfully, before yesterday, I’m not sure I could have told you whether I liked seaweed, smoked or otherwise.

I do like sushi, but the seaweed within a maki roll has always seemed more functional than flavorful– a necessary material to keep the whole thing held together.

But when I heard about yesterday’s Experimental Cuisine Collective meeting– “The Science of Sushi and Seaweed”– I couldn’t resist. The speaker’s day job is as a biophysicist at a Danish university, and he haunts sushi restaurants (and even writes a book) in his spare time. Perfect.

And so I spent yesterday afternoon at a sushi science talk and algae tasting. Seaweeds are algae after all, not plants. So though many algae synthesize food from the sun, unlike plants, seaweeds are complexes of single cells. Plants are interdependent multicellular organisms– seaweed are communities of independent operators.

Ole Mouritsen talked in a lovely cultural and scientific hodgepodge– part cultural history and part science. The flavors of sushi– the sweetness of the rice, the sour from the vinegar– date back to old methods for preserving fish. Though no longer necessary, those lingering elements of taste are part of the sushi experience. A tidbit about wasabi– though it may be fiery– its punch comes from isothiocyanates (funky molecular structures that have carbon, nitrogen and sulfur lined up next to each other). But unlike other molecules that set our taste buds on fire (capsaicin in chili peppers, for example), isothiocyanates are water soluble. That’s why you can actually cleanse your palate pretty easily if you get a little too much of the evil green stuff.

But back to the seaweed. I’m definitely not ready to become an algaetarian, but seaweed definitely makes an interesting, sometimes pungent garnish. Nori– the ubiquitous sushi wrapping– is actually paper-like, easily torn. But when wrapped around sushi rice, it quickly absorbs water and the complex sugars become gummy. The Japanese annually fete Kathleen Mary Drew-Baker, the British botanist who figured out how to culture this particular algae.

Oboro kombu looks a little like vacuum cleaner lint and melts in your mouth like umami cotton candy. And then there’s the dulse– dark red, tangy, particularly the almost bacony applewood-smoked version. Don’t forget to sniff first.

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Introducing Material of the Week: Spider Silk

24 Sep
Madagascar golden orb spider (Nephila madagascariensis)

Madagascar golden orb spider (Nephila madagascariensis) Photo by Rhett A. Butler

Followers of this blog might have noticed that the Molecule of the Week (MotW) feature took a summerish hiatus. I’ve decided to expand the feature to include interesting materials, which are often more complex mixtures, either of synthetic or naturally-made compounds. So, I’m adding Material of the Week (MatotW in blogospheric shorthand) to help round out the idea.

This week, a material near and dear to my Webby heart: spider silk.

The American Museum of Natural History in New York is now displaying a length of cloth made entirely from Madagascar golden orb spider silk . At a half million dollar price tag and requiring 1 million spiders, this is the fabric of kings (maybe even Louis XIV) and involves some some serious production snags (See the NY Times or Wired Science for more on those issues).

The silks are made of structural proteins, chains of amino acid building blocks, that in different combinations do the work of living systems and make up other sorts of animal fibers such as hair. The animals use different combinations for different purposes: making webs, catching prey, building nests, or wooing a mate, notes Cheryl Hayashi’s UC Riverside website. (She studies these materials and garnered a MacArthur grant in 2007 for her work).

istockphoto/Taho_H

istockphoto/Taho_H

I’m already making plans to go see the spider silk fabric (and still trying to imagine lining up spiders in harnesses to produce it– quite the mental image). But spider silk reminds me of how much we humans can learn from our fellow inhabitants on this planet. Sure, the military and industry might find all sorts of uses for these threads from armor to moorings. But in this moment I’m simply awed by the natural engineering process and its outcome — a spider hanging from a single super-strong thread, spinning a lacy net to catch prey, and a few dew drops.

Reflecting E.B. White’s words back on Charlotte: “Some Web.”