Life's quantum mechanisms (Introduction)

by David Turell @, Friday, November 10, 2017, 22:26 (10 days ago)

Weird quantum effects are so delicate it seems they could only happen in a lab. How on Earth can life depend on them? (my bold)

"Schrödinger wrote in What Is Life? (1944), some of life’s most fundamental building blocks must, like unobserved radioactive atoms, be quantum entities able to perform counterintuitive tricks. Indeed, he went on to propose that life is different from the inanimate world precisely because it inhabits a borderland between the quantum and classical world: a region we might call the quantum edge.


"Olfactory receptors might be responding to molecular vibration. This idea received a further quantum twist in 1996, when the biophysicist Luca Turin proposed that vibrations might promote quantum tunnelling of electrons to open the olfactory lock. A quantum theory of smell sounds outlandish, perhaps, but evidence has recently emerged to support it: it was found that fruit flies can distinguish odorants with exactly the same shape but different isotopes of the same elements, something that is hard to explain without quantum mechanics.


"Schulten discovered that entangled pairs of particles can be extraordinarily sensitive to both the strength and the orientation of magnetic fields. He went on to propose that the enigmatic avian compass might be using quantum-entangled particles. Hardly anyone took the idea seriously, but in 2000, Schulten wrote an influential paper with his student, Thorsten Ritz, showing how light could be used to make a quantum-entangled compass in a bird’s eye. In 2004, Ritz teamed up with the celebrated husband-and-wife ornithologists Wolfgang and Roswitha Wiltschko, and together they found compelling experimental evidence that the European robin was indeed using Einstein’s spooky action to find its way around the globe every year.


"Take enzymes. These are the workhorses of the living world, speeding up chemical reactions so that processes that would otherwise take thousands of years happen inside living cells in seconds. How they achieve this speed-up – often more than a trillion-fold – has long been an enigma. But now, research by Judith Klinman at the University of California, Berkeley and Nigel Scrutton at the University of Manchester (among others) has shown that enzymes can employ a weird quantum trick called tunnelling. Simply put, the enzyme encourages a process whereby electrons and protons vanish from one position in a biochemical and instantly rematerialise in another, without visiting any of the in-between places – a kind of teleportation.


"When the team shone the laser at the system, they observed a very peculiar light echo that came in beat-like waves. These ‘quantum beats’ were a sign that, instead of taking a single route through the system, the photon energy was using quantum coherence to travel by all possible routes simultaneously. Imagine if, when confronted by the stream, the famous cat somehow divided itself into lots of identical quantum-coherent cats that hop across the chlorophyll boulders by every available route to find the quickest one. Quantum beats have now been detected in many different photosystems, including those of regular plants such as spinach. It appears that the most important reaction in the biosphere is exploiting the quantum world to put our food on our table.


"Beneath all these quantum solutions to puzzling vital phenomena, we find ourselves with a deeper mystery. Quantum coherence is an immensely delicate phenomenon, depending on those in-tune particle waves. To maintain it, physicists usually have to enclose their systems within near-perfect vacuums and cool them down to very close to absolute zero temperature to freeze out any heat-driven molecular motion. Molecular vibrations are the mortal enemy of quantum coherence. How, then, does life manage to maintain its molecular order for long enough to perform its quantum tricks in warm and wet cells? That remains a profound riddle. Recent research offers a tantalising hint that, instead of avoiding molecular storms, life embraces them, rather like the captain of a ship who harnesses turbulent gusts and squalls to maintain his ship upright and on-course. As Schrödinger predicted, life navigates a narrow stream between the classical and quantum worlds: the quantum edge."

Comment: Quite a long article. I've presented nuggets of living quantum processes. The entire universe is based on mysterious quantum mechanics. Note my bold at the beginning. Life uses quantum processes easily, yet they require delicate lab controls to be studied. God creates thru the quantum mystery.

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