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.
This is pretty fundamental stuff. Enzymes made every single biomolecule in every cell of every living creature on the planet. They are, more than any other component (even DNA, given that some cells get by without it) the essential ingredient of life. And they dip into the quantum world to help keep us alive.
Photosynthesis uses quantum coherence:
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.
If so, it makes sense. The quantum world exists, whether anything uses it or not, but in nature everything tends to get used.
The author, Johnjoe McFadden and physicist Jim Al-Khalili hope to apply quantum mechanics to evolution by adaptive mutation, “ which appears to occur more frequently when it provides an advantage.” Mmmm. Wasn’t Darwin supposed to have explained that? Oh wait …
Hat tip: Stephanie West Allen at Brains on Purpose