Cracking open a cold can of Coke and taking a bubbling swig will have your taste buds dancing—and now scientists know why. A new study shows that cells in taste buds that respond to sour stimuli also seem to be the ones responsible for tasting the carbonation’s fizz [NPR].The fact that we can taste the carbon dioxide in a fizzing soda has previously puzzled scientists, since the human tongue is usually thought to only sense five flavors—bitter, sweet, salty, sour, and umami (also called savory). However, the new study, published in Science, shows that the sour taste buds have an enzyme that interacts with carbon dioxide, so it’s not the bursting bubbles that you taste, it’s the C02 itself.
The researchers discovered this tricky bit of chemistry by studying mice. They gave the animals sips of club soda or a little buzz of carbon dioxide gas and recorded how the tongue signaled the sensation to the brain. Both soda and the gas produced similar sensations. But when they tested mice bred to have no sour taste buds, the brain never got its sensory alert. Further probing uncovered the enzyme responsible [AP]. The mechanism should be the same in humans, according to the scientists.
A new surface coating could mean the end of roach traps as we know them. The plastic-like material, called a polyimide resin, is like a Slip ‘n Slide for the normally sure-footed roaches. Insects naturally secrete a fluid that’s an emulsion of oily and watery liquids that helps them stick to almost any surface. The scientists’ polyimide coating absorbs the watery part, cutting bugs’ friction on vertical surfaces by about 40 percent [Popular Science].
In an experiment, a rod with an apple on top was painted with a number of different chemicals, including the polyimide resin. Scientists observed roaches climbing to reach the apple, and measured the friction between the roaches feet and the rod. They found that roaches effortlessly shimmied up rods coated in PTFE, a non-stick coating commonly found on cooking pans. But when the rods were covered in polyimide resin, the creatures lost their grip [New Scientist].
Two American men and an Israeli woman have won the Nobel Prize for chemistry for work that probed the structure of the ribosome, the cell’s protein factory. Venkatraman Ramakrishnan, Thomas Steitz, and Ada Yonath worked separately to understand one of life’s core processes: the method by which ribosomes translate genetic code into proteins, the building blocks of all organisms.
Their work revealed what ribosomes, which produce proteins that control the chemistry in all living organisms, look like and how they function at the atomic level. The Laureates also created three-dimensional models that show how different antibiotics bind to the ribosome, research that has been used to develop new anti-infective medicines [Bloomberg].
Scientists have found another reason why the fizz in a glass of champagne is so important: Besides tickling the tongue and pleasing the eye, the bubbles also release aromatic compounds that they’ve dragged up from the liquid in the glass. A new study found that concentrations of certain chemical compounds are higher in the air just above the glass than in the actual champagne.
Wine expert Jamie Goode comments: “In the past, we thought that the carbon dioxide in the bubbles just gave the wine an acidic bite and a little tingle on the tongue, but this study shows that it is much more than this” [BBC News]. Smelling the chemical compounds enhances the overall flavor of the champagne, researchers say.
With a lot of skillful maneuverings, a team of researchers have finally found a way to image a molecule. The portrait of pentacene, an organic molecule consisting of five benzene rings, shows off the chemical bonds between the carbon and hydrogen atoms.
It may seem a somewhat surprising first, since atoms have been imaged for decades. The earliest pictures of individual atoms were captured in the 1970s by blasting a target – typically a chunk of metal – with a beam of electrons, a technique known as transmission electron microscopy (TEM)…. But strange though it might seem, imaging larger molecules at the same level of detail has not been possible – atoms are robust enough to withstand existing tools, but the structures of molecules are not [New Scientist].
In the new study, published in Science, researchers used an atomic force microscope to image the molecule in unprecedented resolution. The measurement requires extremes of precision. In order to avoid the effects of stray gas molecules bounding around, or the general atomic-scale jiggling that room-temperature objects experience, the whole setup has to be kept under high vacuum and at blisteringly cold temperatures [BBC News]; 5 Kelvin, to be exact. Rather than relying on an optical system to produce pictures, atomic force microscopes use a probe that narrows to an atomic-scale tip, and measures the forces of attraction between the tip and the molecule’s components.
Nitrous oxide, also known as laughing gas, might sound like a humorous substance. But here’s a sobering fact: The chemical now poses the largest man-made threat to the ozone layer, according to a study published in Science. Environmental policies, which have focused on controlling emissions of compounds such as CFCs, have largely ignored nitrous oxide. CFC levels have been falling since the 1989 adoption of the Montreal Protocol on Substances that Deplete the Ozone Layer… Meanwhile, nitrous oxide levels have been climbing as a result of increased emissions from agricultural fertilizers, biomass burning and animal waste [Nature News].
Researchers used a model to compare the potential of various gases, including laughing gas, to deplete the ozone layer, compared to a compound called CClF3, a substance with one of the greatest potentials for destroying the ozone. They found that although the threat that nitrous oxide poses to ozone is small compared to CClF3, the large-scale emissions of laughing gas mean it is the most significant of the ozone-depleting substances emitted by human-related activities today…. “This is the first time someone has dealt with nitrous oxide in isolation like this,” says atmospheric chemist Susan Solomon. “It’s one of those things that has simply been overlooked” [Nature News].
A humble marine worm may hold the key to mending bones that have been shattered: a strong adhesive that the worm uses to build its shell, and which hardens despite the worm’s watery habitat. Sandcastle worms, Phragmatopoma californica, dwell in the intertidal zone where they construct a tubelike shell by gluing together bits of sand, broken shells and other mineral debris. The glue is secreted from a special gland and hardens in less than 30 seconds underwater, forming a leatherlike consistency over several hours [Science News].
Medical engineer Russell Stewart has been working on a synthetic glue modeled on the worm’s adhesive. He thinks the worm-inspired glue could be just the thing for piecing together the small fragments of bone that result from complex breaks that must be glued within the wet environment of the body. “There’s lots of synthetic adhesives in widespread use for other things, [but] there’s no adhesives used for deep tissue repair,” Stewart said. Current remedies are primarily mechanical fixes, such as screws, pins, and plates, which can be an inefficient method for repairing highly fractured bones [The Scientist].
In chunks of rock quarried from a Russian mountain range, physicists have found perfect “quasicrystals,” a type of material that researchers previously thought could only be created in a lab. Quasicrystals display ordered arrangements and symmetries but are not periodic—that is, they are not defined by a single unit cell (such as a cube) that simply repeats itself in three dimensions [Scientific American]. Instead, quasicrystals have two different geometric structures that alternate, and that are organized in ways which create complex patterns and symmetries. When such a pattern is laid out in two-dimensions, the resulting design is often called Penrose tiling.
Quasicrystals were first created in the lab in 1984, and physicist Paul Steinhardt, a coauthor of the current study, says the hunt for naturally occurring quasicrystals began about 10 years ago. “The latest issue surrounding quasicrystals has been could nature ever make them? … When we make them in the lab we try very hard to make perfect quasicrystals, but nature has no such goal” [Discovery News]. The researchers put out a call to mineralogists around the world, asking them to send in likely rock samples for testing.
Using a fancy piece of chemistry equipment to study the chemical composition of wine, European researchers have one-upped the sophisticated palates of wine connoisseurs. The researchers used ultra high resolution mass spectrometry to sort through all the chemical compounds present in wines that had been aged in oak barrels, and found that for each wine, they could determine which French forest the oak was cut from. No other approach – analytical or sensory – has been able to significantly discriminate wines according to the species or the origin of the oak used for the barrels before, they say [Chemistry World].
The findings could prove useful to wine connoisseurs and historians, the researchers said, concluding that their findings produced “chemical representations of the way such noble nectar can shape, on the (tongue) of the wine taster, some of the outlines of the scene of its birth” [AP]. Similar analyses could also be used to detect wine fraud, the researchers noted.
“LOOK MOM NO ELECTRICITY.” That was the first message conveyed by a rudimentary new communication system that researchers are calling the “infofuse.” In a new study, researchers printed patterns of three different flammable metallic salts on a nitrocellulose fuse and then set the fuse on fire. As it burned, it emitted pulses of different colored light that can be interpreted with a Morse code system.
In the study, published in the Proceedings of the National Academy of Sciences, researchers explain that they developed a code for the alphabet, numbers and four special characters (a full-stop, comma, exclamation mark and the “@” sign) based on the presence or absence of one of the three metals in each dot. Extra coding information comes from the length of the dot, which determines the duration with which it burns, and the space between dots, where no colour is produced [New Scientist]. They placed dots of the three metals–lithium, rubidium, and caesium–on the paper using an ordinary ink-jet printer. When the infofuse was set alight, its precise patterns were “read” by an optical detector.
Wouldn’t it be useful if an aging, weakening bridge started to turn red as a warning to structural engineers? That’s the potential inherent in a new invention from a team of chemists and materials scientists, who created a plastic that turns red when it’s exposed to stress. Ultimately, such color-changing polymers could be used as coatings on everything from bridges to airplane wings, alerting engineers when vital structures are near failure [ScienceNOW Daily News].
To make the red-alert plastics, researchers placed small ring-shaped molecules that they call “mechanophores” in the center of polymer chains. In response to mechanical force, these rings break, changing the color of the polymer [ScienceNOW Daily News].
A new study has found higher than expected levels of a controversial plastics chemical in people who had fasted for 24 hours. This surprised researchers because the chemical, bisphenol A (BPA), was thought to be ingested when trace amounts leaked from plastic food containers and bottles, and researchers thought it quickly passed through the system.
The finding suggests that exposure to BPA may come from many different sources, not just food products, or that the body doesn’t metabolize the chemical as fast as has been thought, the researchers said…. “What this study shows is that either we are getting exposed to a lot more BPA than we thought, or it’s hanging around longer than we thought, or both,” said lead researcher Dr. Richard W. Stahlhut [HealthDay News].
When two people get knocked off their feet by physical chemistry, their friends may offer this standard glib explanation: “It’s all about the pheromones.” But in fact, 50 years after the term “pheromones” was coined by biologists to refer to the chemical messages passed within many insect and mammal species, researchers still haven’t found proof that humans emit or detect such chemicals. In an essay in Nature [subscription required] marking the 50-year milestone, zoologist Tristram Wyatt sums up the state of the research, and reminds the gullible not to buy any love potions that boast of their pheromone content.
The first studies took place in 1959, when German researchers discovered a chemical called bombykol that’s secreted by female silk moths and that immediately sends males into a mating frenzy. Following that Nobel Prize-winning work, biologists proceeded to find pheromones “across the animal kingdom, sending messages between courting lobsters, alarmed aphids, suckling rabbit pups, mound-building termites and trail-following ants. They are also used by algae, yeast, ciliates and bacteria” [Wired News], Wyatt writes. Pheromones have been found to play a part not just in mating rituals, but also battles for dominance, warnings about approaching danger, and cooperative behavior.
By tweaking chemical strands of RNA, researchers have taken another step towards understanding how life may have first evolved on our planet. A test tube based system of chemicals that exhibit life-like qualities such as indefinite self-replication, mutation, and survival of the fittest, has been created by US scientists…. “This is the very end of the line, where chemistry starts turning into biology” [Chemistry World], says researcher Gerald Joyce. Researchers have previously created RNA strands that replicated themselves for a while before grinding to a halt, but this experiment marks the first creation of RNA strands that continue to replicate themselves indefinitely, which set up the conditions that allowed for evolution.
In the modern world, DNA carries the genetic sequence for advanced organisms, while RNA is dependent on DNA for performing its roles such as building proteins. But one prominent theory about the origins of life, called the RNA World model, postulates that because RNA can function as both a gene and an enzyme, RNA might have come before DNA and protein and acted as the ancestral molecule of life [Astrobiology Magazine].
A synthetic material that mimics the qualities of an iridescent opal may have wide-reaching technological applications, its creators say. With the application of an electric current the material can rapidly change to any color of the spectrum, and the developers, who said they’re ready to sell the technology today, added that their ‘photonic ink’ (P-Ink) material could soon be used in electronic books or advertising displays [ZDNet].
The synthetic material can be likened to an opal, a mineral that owes its variety of colours to its layered structure: regions with a high refractive index, in which light travels slowly, are interleaved with regions with a low refractive index. Light waves with a wavelength – or colour – similar to that of the space between layers are scattered in a way that gives opal its iridescent sheen [New Scientist]. The synthetic material has a similarly layered structure, but with the addition of a little voltage the space between the layers swells or shrinks, allowing for fine-tuned control of what color of light the material scatters.
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Cracking open a cold can of Coke and taking a bubbling swig will have your taste buds dancing—and now scientists know why. A new study shows that cells in taste buds that respond to sour stimuli also seem to be the ones responsible for tasting the carbonation’s fizz [NPR].The fact that we can taste the carbon dioxide in a fizzing soda has previously puzzled scientists, since the human tongue is usually thought to only sense five flavors—bitter, sweet, salty, sour, and umami (also called savory). However, the new study, published in Science, shows that the sour taste buds have an enzyme that interacts with carbon dioxide, so it’s not the bursting bubbles that you taste, it’s the C02 itself.
Two American men and an Israeli woman have won the 
Scientists have found another reason why the fizz in a glass of 
With a lot of skillful maneuverings, a team of researchers have finally found a way to image a molecule. The portrait of pentacene, an organic molecule consisting of five benzene rings, shows off the chemical bonds between the carbon and hydrogen atoms.
Nitrous oxide, also known as laughing gas, might sound like a humorous substance. But here’s a sobering fact: The chemical now poses the largest man-made threat to the ozone layer, according to a 
A humble marine worm may hold the key to mending bones that have been shattered: a strong adhesive that the worm uses to build its shell, and which hardens despite the worm’s watery habitat. Sandcastle worms, Phragmatopoma californica, dwell in the intertidal zone where they construct a tubelike shell by gluing together bits of sand, broken shells and other mineral debris. The glue is secreted from a special gland and hardens in less than 30 seconds underwater, forming a leatherlike consistency over several hours [
In chunks of rock quarried from a Russian mountain range, physicists have found perfect “quasicrystals,” a type of material that researchers previously thought could only be created in a lab. Quasicrystals display ordered arrangements and symmetries but are not periodic—that is, they are not defined by a single unit cell (such as a cube) that simply repeats itself in three dimensions [
Using a fancy piece of chemistry equipment to study the chemical composition of 
“LOOK MOM NO ELECTRICITY.” That was the first message conveyed by a rudimentary new communication system that researchers are calling the “infofuse.” In a new study, researchers printed patterns of three different flammable metallic salts on a nitrocellulose fuse and then set the fuse on fire. As it burned, it emitted pulses of different colored light that can be interpreted with a Morse code system.
Wouldn’t it be useful if an aging, weakening bridge started to turn red as a warning to structural engineers? That’s the potential inherent in a new invention from a team of chemists and materials scientists, who created a plastic that turns red when it’s exposed to stress. Ultimately, such color-changing polymers could be used as coatings on everything from bridges to airplane wings, alerting engineers when vital structures are near failure [
A new study has found higher than expected levels of a controversial 
When two people get knocked off their feet by physical chemistry, their friends may offer this standard glib explanation: “It’s all about the 
By tweaking chemical strands of RNA, researchers have taken another step towards understanding how 
A synthetic 
