Quantum Goo

'Quanta' comes from the Greek; meaning parcels or packets, later its use has been used to describe the very small particles which compose the matter that we and everything we can see and touch are made of. The quantum world is one of strangeness; whereby particles can tunnel through walls, be in several places at once and even entangled particles across large distances can 'communicate' with speeds faster than laws allow. The macro world however, is one of wet, squishy and predictable interactions, slow movements, and very well understood mechanisms. The contrasts couldn't be greater, and yet, one is the prerequisite of the other; quanta makes up matter.

Quantum mechanics had its heyday in the mid 1920's, and at the time was conceived with great astonishment; as the world of the small were so different to the world we knew. Since then, a lot of progress has come in understanding the systems involved, postulating mechanical theories which go to predict atomic behaviour, and expanding the scope of how these nano particles operate.

Progress has been instrumental to the modern world; without the success of the equations of quantum mechanics in describing how electrons move through materials such as semiconductors we would not have developed the silicon transistor and, later, the microchip and the modern computer.

Now, we have a possible new avenue for research, one that deals with the very fundamentals of you - the way nature works and the way organisms may harness some of the strangeness of quanta for their own competitive edge.

The idea that plants and animals may already be carrying out such superfast quantum operations within their own cells, did not seriously cross the minds of either physicists or biologists, even though cells are made up of atoms and, at a basic level, all atoms obey quantum mechanics. The main reason was that, as the would-be builders of quantum computers discovered, quantum effects are extremely fragile. To maintain superposition in the lab, physicists need to cool their systems down to almost absolute zero, the lowest temperature possible, because heat can destroy quantum features. So there seemed little chance that these quantum properties could survive in the balmy temperatures within living cells.

70 years ago, the Austrian Nobel prize-winning physicist and quantum pioneer, Erwin Schrödinger, suggested in his famous book, 'What is Life?', that, deep down, some aspects of biology must be based on the rules and orderly world of quantum mechanics. His book inspired a generation of scientists, including the discoverers of the double-helix structure of DNA, Francis Crick, James Watson and the often forgotten about Rosalind Franklin – who died soon after the publication, but was responsible for the x-ray diffraction image 'photo 51'.

Schrödinger proposed that there was something unique about life that distinguishes it from the rest of the non-living world. He suggested that, unlike inanimate matter, living organisms can somehow reach down to the quantum domain and utilise its strange properties in order to operate the extraordinary machinery within living cells.

But this was mostly disregarded; the science of quantum mechanics had too much on its plate to deal with a correlation which couldn't be accounted for. The idea that biology - impossibly warm, wet and messy to your average physicist - should play host to these states was almost heretical. Even though the field had some very well respected quantum physicists on board (Niels Bohr, Pascual Jordan, Max Delbruck and Per-Olov Lowdin) it has only taken until now that this field has been re-examined, particularly after having the distinguished Al-Khalili (Theoretical physicist, presenter, spokesman) spearhead the movement, much to the bemusement of his fellow peers. It is only in the past decade or so that a small but dedicated band of physicists and biologists has found hints that nature may also use these rules to enhance the efficiency of biological tasks.

The paper 'A quantum mechanical model of adaptive mutation' (1999), caused a bit of a stir when it came out, isolating aspects of nature which utilises quantum strangeness to perform certain tasks. This is what i'm going to talk about. Though Al-Khalili and McFadden did not label it as such at the time, their paper was one of the first in the now burgeoning field of quantum biology. The strange rules that control the subatomic world might be unintuitive, but they have been verified through many experiments for the better part of a century.

Photosynthesis:

You may have been told roughly what is photosynthesis and how it generally works, but to understand how it really works is to understand that there is something odd happening with the way the photon and the reaction centre. Watch the process closely enough and it appears there are little packets of energy simultaneously "trying" all of the possible paths to get where they need to go, and then settling on the most efficient.

The initiating event is the capture of light energy by a chlorophyll molecule and its conversion into chemical energy that is harnessed to fix carbon dioxide and turn it into plant matter. The process whereby this light energy is transported through the cell has long been a puzzle because it can be so efficient – close to 100% and higher than any artificial energy transport process. Biologists had assumed that the energy hopped from molecule to molecule along a single pathway. But calculations showed that this could account only for about a 50 percent efficiency rate. To explain the near-perfect performance of plants, biophysicists reasoned, the energy must exist in a quantum superposition state, travelling along all molecular pathways at the same time. An ingenious experiment, first carried out in 2007 in Berkley, California, probed what was going on by firing short bursts of laser light at photosynthetic complexes. The research revealed that the energy packet was not hopping haphazardly about, but performing a neat quantum trick. Instead of behaving like a localised particle travelling along a single route, it behaves quantum mechanically, like a spread-out wave, and samples all possible routes at once to find the quickest way.

Because the efficiency rate was so high, there was something at work here that pervades the process of simply trying out where the reaction centre. The reaction centre is small and so is the photon, so for the two to 'mingle' would require a trick only known to the quantum world.

Enzymes for metamorphosis:

Enzymes are the workhorses of life. They speed up chemical reactions so that processes that would otherwise take thousands of years proceed in seconds inside living cells. Life would be impossible without them. But how they accelerate chemical reactions by such enormous factors, often more than a trillion-fold, has been an enigma. Experiments over the past few decades, however, have shown that enzymes make use of a remarkable trick called 'quantum tunnelling' to accelerate biochemical reactions. it should be stressed that quantum tunnelling is a very familiar process in the subatomic world and is responsible for such processes as radioactive decay of atoms and even the reason the sun shines (by turning hydrogen into helium through the process of nuclear fusion).

Essentially, the enzyme encourages electrons and protons to vanish from one position in a biomolecule and instantly rematerialise in another, without passing through the gap in between – a kind of quantum teleportation. The example given when I watched 'The secrets of quantum physics, let there be life' (2014) was that of the frog. The innocent warm, wet and messy frog. There is a stage early on in its life where it transforms from tadpole to frog, and it is here that this quantum tunnelling comes into play; without it it would take immense amounts of energy, but also immense amounts of time to break these bonds of the tadpoles form. It is only when you introduce quantum processes that it begins to make sense.

Enzymes have made every single biomolecule in your cells and every cell of every living creature on the planet, so they are essential ingredients of life. And they dip into the quantum world to help keep us alive, how nuts is that!?

Migration through an internal magnetic compass:

We all know that migration happens, and it is so common-place that it seems barmy to question the processes behind it, and yet, there are aspects of it which still have scientists scratching their eccentric hairdo's in confusion.

For instance, the unassuming Robin. Experiments show that European robins only oriented themselves for migration under certain colours of light, and that very weak radio waves could completely mix up their sense of direction. Neither should affect the standard compass that biologists once believed birds had within their cells, and yet, it does.

Unlike many other species of migratory birds, marine animals and even insects, Robins do not rely on landmarks, ocean currents, the position of the sun or a built-in star map. Instead, they are among a select group of animals that use a remarkable navigation sense – remarkable for two reasons. The first is that they are able to detect tiny variations in the direction of the Earth’s magnetic field – astonishing in itself, given that this magnetic field is 100 times weaker than even that of a measly fridge magnet. The second is that robins seem to be able to “see” the Earth’s magnetic field via a process that even Albert Einstein referred to as “spooky”. The birds’ in-built compass appears to make use of one of the strangest features of quantum mechanics.

One proposed mechanism for magneto-reception is based on the radical pair mechanism which involves the quantum dynamics of electrons in interaction with their nuclear spin environment. This comes under the grounds of 'entanglement'; whereby a pair of electrons which are entangled, interact with each-other instantly over vast distances. When one entangled particle is spinning one way, then the other automatically spins the other. The process could work via light-triggered interactions on a chemical in bird’s eyes; as entangled particles could manifest in each eye to create a chain reaction. Light would excite two electrons on a molecule in the bird’s eye, switching one onto a second molecule, but the two would remain entangled even though they’re separated.

Olfaction sensing (smell):

The way we smell has been 'understood' for a relatively long time (in terms of modern science), as the molecule (smell) is inhaled and is received by receptors to determine what exactly that bit of matter was. The receptors are all part of our olfactory centre and essentially are pre-programmed into our system; whereby you cannot smell something you aren't designed to smell. The problem comes however, when you have two molecules of the same 'shape', but different 'vibration'.

A paper published in 'Plos One' shows that people can tell the difference between two molecules of identical shape but with different vibrations, suggesting that shape is not the only thing at work.

But Dr Luca Turin believes that the way smell molecules wiggle and vibrate is responsible - thanks to the quantum effect called tunnelling. The idea holds that electrons in the receptors in our noses disappear on one side of a smell molecule and reappear on the other, leaving a little bit of energy behind in the process.

Though the debate here goes on...

Professor Leslie Vosshall:

"I like to think of the vibration theory of olfaction and its proponents as unicorns. The rest of us studying olfaction are horses," she told BBC News. "The problem is that proving that a unicorn exists or does not exist is impossible. This debate on the vibration theory or the existence of unicorns will never end, but the very important underlying question of why things smell the way they do will continue to be answered by the horses among us."

Conclusion:

All these quantum effects have come as a big surprise to most scientists who believed that the quantum laws only applied in the microscopic world. All delicate quantum behaviour was thought to be washed away very quickly in bigger objects, such as living cells, containing the turbulent motion of trillions of randomly moving particles. So how does life manage its quantum trickery? Recent research suggests that rather than 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.

Just as Schrödinger predicted, life seems to be balanced on the boundary between the sensible everyday world of the large and the weird and wonderful quantum world, a discovery that is opening up an exciting new field of 21st-century science.

The field also allows for a new perspective of biological operations, so it doesn't stop merely at uncovering the examples to confirm the theory, but also to initialise the mechanics (if we can) in a way to try and solve some of the more problematic and lingering issues relating to biological processes:

“The holy grail is to find that quantum effects stimulate biological processes that are relevant to medicine,” says Al-Khalili. “Looking to the long term, if these effects underlie the mechanism of DNA mutations, that could allow for real progress in the treatment of cancer.”

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