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Schrödinger argued that it is not only the gas laws that derive their accuracy from the statistical properties of large numbers; all the laws of classical physics and chemistry—including the laws governing the dynamics of fluids or chemical reactions—are based on this “averaging of large numbers” or “order from disorder” principle.
The behavior of a very tiny balloon will thereby be largely unpredictable.
Schrödinger went further than simply observing that the statistical laws of classical physics could not be relied on at the microscopic level: he quantified the decline in accuracy, calculating that the magnitude of deviations from those laws is inversely proportional to the square root of the number of particles involved.
Much of the skepticism Schrödinger’s claim attracted at the time was rooted in the general belief that delicate quantum states couldn’t possibly survive in the warm, wet and busy molecular environments inside living organisms.
This process by which random molecular motion disrupts carefully aligned quantum mechanical systems is known as decoherence, and it rapidly wipes out the weird quantum effects in big inanimate objects.
This is what Jordan termed amplification and Schrödinger called order from order.
No inanimate macroscopic object in the known universe has this sensitivity to the detailed structure of matter at its most fundamental level—a level where quantum mechanical rather than classical laws reign. Schrödinger argued that this is what makes life so special.
Everything that living things do can be understood in terms of the jiggling and wiggling of atoms … RICHARD FEYNMAN1
But conventional soft-tissue fossils preserve only the impression of biological tissue, not its substance; yet the pliable material that remained in Mary Schweitzer’s acid bath appeared to be the dinosaur’s soft tissue itself.
The collagenase enzyme that Mary Schweitzer added to her dinosaur bones is just one of these biomachines whose regular job in animal bodies is to disintegrate collagen fibers. The rate of speed-up provided by enzymes can be roughly estimated by comparing the time taken to digest collagen fibers in their absence (clearly, more than sixty-eight million years) and in the presence of the right enzyme (about thirty minutes): a trillion-fold difference.
Peptide bonds are very strong; after all, those that held the T. rex collagen fibers together had survived for sixty-eight million years.
extracellular matrix
Peptide bonds between the amino-acid beads of collagen fibers are the difference between Marshmallow Man and Tyrannosaurus rex. Tough collagen fibers make real animals tough.
If a house is damaged by a storm or an earthquake, repair has to be preceded by stripping out the broken framework. Similarly, animal bodies use the enzyme collagenase to cut away damaged parts of the extracellular matrix so that the tissue can be repaired—by another set of enzymes.
Its action in cheese-making is to cause milk to coagulate so it can be separated into curds and whey; but its natural role in a young calf’s body is to curdle the milk it ingests so that it remains longer in the digestive tract, giving more time for it to be absorbed.
It shows up as a clam-like structure clamped onto one of the collagen fibers, and slides down the fiber, unzipping the triple helix strands before simply clipping apart the peptide bonds connecting the amino-acid beads.
The choreographed action taking place within this molecular steering center is very different from all the random jostling going on outside and around the enzyme, and it plays a disproportionately important role in the life of the entire frog.
A reaction that might otherwise take upward of sixty-eight million years has been completed in nanoseconds.
Here, highly structured biomolecules interact in very specific ways with other highly structured biomolecules.
This can be seen as either Jordan’s dictatorial amplification or Erwin Schrödinger’s “order from order” that goes all the way down from the developing frog through its organized tissues and cells down to the fibers that hold those tissues and cells together and the choreographed motion of fundamental particles within the active site of collagenase that remodels those fibers and thereby affects the development of the entire frog.
But does this molecular order allow a different set of rules to come into play in life, as Schrödinger claimed?
Is enzyme catalysis just a collection of several straightforward classical catalytic mechanisms packed into active sites, thereby providing the vital spark that ignites life?
The essence of oxidation is movement of electrons from a donor to an acceptor molecule.
This capturing of the electron energy in small chunks makes the whole process much more efficient than simply pouring it directly into oxygen, as very little of it is lost as waste heat.
Each electron transfer event, between one enzyme and the next in the relay, takes place across a gap of several tens of angstroms—a distance of many atoms—much farther than was thought to be possible for conventional electron-hopping.
An important feature of quantum mechanics is that the lighter the particle, the easier it is for it to tunnel.
Quantum tunneling also explained how radioactive decay takes place: when certain atomic nuclei such as those of uranium occasionally spit out a particle.
A crucial feature of quantum tunneling is that, like many other quantum phenomena, it depends on the spread-out wave-like nature of matter particles. But for a body made up of very many particles to tunnel it has to maintain the wave aspects of all its constituents marching in step, with peaks and troughs of waves coinciding, something we refer to as the system being coherent, or simply “in tune.” Decoherence describes the process whereby all the many quantum waves very rapidly get out of step with one another and wash away any overall coherent behavior, thus destroying the body’s ability to
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Hopfield therefore suggested that at these lower temperatures the electron is raised to a state sitting halfway up the energy slope, where the distance it needs to traverse is shorter than it is at the bottom of the slope, enhancing its chances of quantum tunneling through the barrier. And he was right: the tunneling-mediated transfer of electrons takes place even at very low temperatures, just as DeVault and Chance found.
But proton tunneling is involved in a few chemical reactions that can be identified by their relative indifference to temperature, just as DeVault and Chance had demonstrated for electron tunneling.
The kinetic isotope effect involves measuring how sensitive a chemical reaction is to the changing of atoms from light to heavy isotopes, and is defined as the ratio of reaction rates observed with heavy and light isotopes.
the reaction may or may not be sensitive to the changing weight of the atoms, depending on the route that the reactants take to be converted into products.
So doubling the mass of the atom, for example changing from normal hydrogen to deuterium, causes its probability of quantum tunneling to plummet.
But if quantum tunneling is involved, then the reaction should also show a peculiar response to temperature: its rate should plateau out at low temperatures, just as DeVault and Chance had demonstrated for electron tunneling.
It has been known for some time that enzymes are not static, but are constantly vibrating during their reactions.
For example, the jaws of the collagenase enzyme open and close every time they break a collagen bond. It was thought that these motions were either incidental to the reaction mechanism or were involved in capturing the substrates and bringing all the reactive atoms into the correct alignment.
However, quantum biology researchers now claim that these vibrations are so-called “driving motions” whose primary function is to bring atoms and molecules into close enough proximity to allow thei...
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Enzymes have made and unmade every single biomolecule inside every living cell that lives or has ever lived. Enzymes are as close as anything to the vital factors of life. So the discovery that some, and possibly all, enzymes work by promoting the dematerialization of particles from one point in space and their instantaneous materialization in another provides us with a novel insight into the mystery of life.
Their argument is often positioned within a debate about whether or not enzymes evolved to take advantage of quantum phenomena such as tunneling.
If you remember, it is this kind of random motion that scatters and disrupts the delicate quantum coherence and makes our everyday world appear “normal” to us.
Quantum coherence would not be expected to survive within this molecular turbulence, so the discovery that quantum effects, such as tunneling, manage to persist in the sea of molecular agitation that is a living cell is very surprising.
Wherever the peak of one wave meets the trough of another they cancel out, resulting in no wave at those points. This is called destructive interference. Conversely, where two peaks or two troughs meet, they reinforce each other, generating twice the wave: this is called constructive interference.
What we now find is that, with each firing of the atom gun that is accompanied by the appearance of a bright dot on the screen, either the left or the right detector beeps, never both.
The atoms are now behaving like conventional particles throughout the experiment. It is as though each atom behaves like a wave when it is confronted by the slits, unless it is being spied upon, in which case it innocently remains as a tiny particle.
We can test this by switching off the left detector. It’s still there, so we would expect its influence to be pretty much the same. But now, with the detector present but switched off, the interference pattern builds up on the screen once again! All the atoms going through the experiment have gone back to behaving as waves. How is it that atoms behaved as particles when the detector over the left slit was switched on, but as soon as it was switched off they behaved like waves? How does a particle going through the right slit know that the detector over the left slit is switched on or off?
In a similar way, the measurement of atoms passing through the two-slit experiment forces them to choose whether to go through the left or the right slit.
In a similar way, the wave function describing an atom going through the two slits tracks the likelihood of finding it anywhere in the apparatus at any given time.
the wave function of the atom in the two-slit experiment is real in the sense that it represents the physical state of the atom itself, which really doesn’t have a specific location unless we measure it and is, until then, everywhere at once—with varying probability, of course, so that we are unlikely to find the atom in places where its wave function is small.
The question then arises: When does the wave function “become” a localized atom once again? The answer is: when we try to detect its location. When such a measurement takes place, the quantum wave function collapses to a single possibility.
Not so for the atom; in the absence of any measurement, the atom really is everywhere.
