FYEAH, CHEMISTRY!

holymoleculesbatman:

X-ray Crystallography

It is a method of determining the arrangement of atoms within a crystal, in which a beam of X-rays strikes a crystal and causes the beam of light to spread into many specific directions. From the angles and intensities of these diffracted beams, a crystallographer can produce a three-dimensional picture of the density of electrons within the crystal. From this electron density, the mean positions of the atoms in the crystal can be determined, as well as their chemical bonds, their disorder and various other information.

X-ray crystallography can locate every atom in a zeolite, an aluminosilicate with many important applications, such as water purification. 

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skaterboytae:

When a honeybee dies it releases a death pheromone, a characteristic odor that signals the survivors to remove it from the hive. This might seem a supreme final act of social responsibility. The corpse is promptly pushed and tugged out of the hive. The death pheromone is oleic acid [a fairly complex molecule, CH3(CH2)7CH=CH(CH2)7COOH, where = stands for a double chemical bond]. 

What happens if a live bee is dabbed with a drop of oleic acid?

Then, no matter how strapping and vigorous it might be, it is carried “kicking and screaming” out of the hive. Even the Queen bee, if she’s painted with invisible amounts of oleic acid, will be subjected to this indignity.

Do the bees understand the danger of corpses decomposing in the hive? Are they aware of the connection between death and oleic acid? Do they have any idea what death is? Do they think to check the oleic acid signal against other information, such as healty spontaneous movement? The answer to all these questions is, almost certainly, No. In the life of the hive there’s no way that a bee can give off detectable whiff of oleic acid other than by dying. Elaborate contemplative machinery is unnecessary. Their perceptions are adequate for their needs.

Ann Druyan & Carl Sagan, Shadows Of Forgotten Ancestors: Who Are We?, What Thin Partitions 

holymoleculesbatman:

Luminol is an organic compound with the molecular formula C₈N₃O₂H₇. In the presence of a catalyst called Potassium Ferricyanide, Luminol reacts with Hydrogen Peroxide to yield Nitrogen gas and 3-Aminophthalic Acid. This product molecule initially forms in an excited state and thus releases energy in the form of a ghostly blue light.

holymoleculesbatman:

Tea lovers! This molecule is called Theanine.

It is commonly found in tea, primarily in green tea. Able to cross the blood-brain barrier, Theanine has psychoactive properties. Theanine has been shown to reduce mental and physical stress, and improves cognition and mood in a synergistic manner with caffeine.

holymoleculesbatman:

This weird shaped molecule is called Ascaridole.

It is a colorless liquid with a pungent smell and taste that is soluble in most organic solvents. It is a component of natural medicine, tonic drinks and food flavoring in Latin American cuisine. As part of the oil, ascaridole is used as an anthelmintic drug that expels parasitic worms from plants, domestic animals and the human body. 

Your life has only just begun.

(photo credit)

via Rajini Rao on Google+, for #ScienceSunday:

‘Smallest rotary motor in biology, the ATP synthase.

All the work done in your body is fueled by breaking a chemical bond in ATP, the “currency of energy”. Did you know that you convert your body weight (or an estimated 50 kg) of ATP per day?!

Where does this ATP come from?

It is synthesized by an incredibly sophisticated molecular machine, the ATP synthase, embedded in the inner membrane of our mitochondria. Energy from the oxidation of food results in protons being pumped across the membrane to create a proton gradient. The protons drive the rotation of a circular ring of proteins in the membrane that in turn move a central shaft. The shaft interacts sequentially with one of 3 catalytic sites within a hexamer, making ATP (little butterflies in the movie!). The ATP synthase rotates about 150 times/second

To visualize the rotation under a microscope, a very long fluorescent rod (actin filament) was chemically attached to the central shaft. Watch real movies (not animations!) of the enzyme spinning here: http://www.k2.phys.waseda.ac.jp/F1movies/F1long.htm

Notice the rotation is slower with longer rods. The rotor produces a torque of 40 pN nm (40 pico Newtons x nanometer), irrespective of the load. This would be the force you would need to rotate a 500 m long rod while standing at the bottom of a large swimming pool at the rate shown in the movie.

How did this amazing rotor evolve?

The hexameric structure is related to DNA helicases that rotate along the DNA double helix, using ATP to unzip the two strands apart. The H+ motor has precedence in flagella motors that use proton gradients to drive rotation of long filaments, allowing bacteria to tumble through their surroundings. At some point, a H+ driven motor came together with a helicase like hexamer to create a rotor driving the hexamer in reverse, to synthesize ATP.

The 1997 Nobel prize in Chemistry was awarded to John Walker and Paul Boyer for solving the structure and cyclical mechanism of the ATP synthase, respectively. This amazing enzyme was also the subject of my own Ph.D. thesis, and my first love!’

For #ScienceSunday curated by +Allison Sekuler and +Robby Bowles

ATP synthase is an amazing little thing. It was, personally, what got me hooked on biochemistry.

via Royal Society of Chemistry:

Scientists in China have used a laser to carve out a pattern of ridges and valleys on layered graphene oxide to mimic two of nature’s tricks in one go - iridescence and superhydrophobicity.

The resulting surface has a magnificent shimmering sheen like the wing of a butterfly or the shell of a beetle, while at the same time collecting water into almost spherical droplets, as a rose petal does. 

In nature many surfaces show superhydrophobicity - where water does not spread but gathers into almost spherical droplets.

This arises because of microscopic ridges and indentations on the surface that traps air and prevents droplets from spreading - as seen in many plant leaves and flower petals.

Similarly, iridescence arises from periodic structures which have order at both the micro- and nanoscale. These act as diffraction gratings that split white light into its constituent wavelengths. In this way a butterfly’s wing can shimmer with different colours while having no inherent pigmentation. 

The Jilin team created iridescent graphene by merging two laser beams to create an interference pattern on the surface of layered graphene oxide. This burned out a series of parallel grooves on the surface, around 2um apart.

Torben Lenau is an expert on biomimetic surfaces at the Technical University of Denmark. ‘If both hydrophobicity and iridescence are needed it is very interesting that they can be achieved in a single operation,’ he says. ‘They talk about liquid transportation in microfluidic systems and biomedical surfaces that stem cells can adhere to. Both obvious needs - and nice to be able to control the degree of hydrophobicity. Concerning the iridescence, I can imagine that it could be an advantage for colour coding. The user will easily know - just by looking at it - if the surfaces are in the right state for flow or cell growth.’