Broken Embraces (2009)
León Ferrari (1920-2013) was an Argentinian conceptual artist who worked with a series of extremely different medias through the years. Trained as an engineer, he gained notoriety in the 1960s thanks to his polemical works on religion and politics. Exiled in 1976 in Brazil, he started a series of plans using heliography, the technique traditionally employed by architects,until the advent of the computers, in order to reproduce their drawings. Combining letraset icons to hand sketches, he invented labyrintic worlds which became part of a series called “The architecture of Madness”.
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 and
ATP synthase is an amazing little thing. It was, personally, what got me hooked on biochemistry.
Marcel Duchamp (1887-1968) was a French artist. He is known for popularizing the “readymade,” objects selected by the artist and presented as an artwork. “The Fountain” was a urinal readymade of his that caused much controversy. L.H.O.O.Q. is another controversial work of his, depicting the Mona Lisa with a moustache, with the title captioned below, pronounced as Elle a chaud au cul translating to ”Her ass is hot/She is really horny.” (Wikipedia)He sometimes painted in the Cubist style and his paintings and drawings often depicted naked ladies. He certainly gave no fucks, and has the side profile of a god.