Quantum Mechanics: Not Just Kinda Cool But Essential to Life

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It has long been clear quantum mechanics (QM) effects are basic in life. This was something I have taken for granted from what I learned starting in pre-med about cellular biology, though research bears this out in many new and interesting ways.

An interesting recent book about some surprising quantum effects in biology i s”Life on the Edge” by McFadden and Al-Khalili.

As I have written here before, life is energy and energy transformations (well, everything is). Cellular life uses reduction/oxidation reactions as energy “currency”. These reactions are basically the passing along of an energetic electron. They are the same kinds of reactions that causes fire to burn (which is why you need oxygen for a fire), or iron to rust. As Nick Lane writes in his book The Vital Question energy, evolution and the origins of complex life:  “electrons [in oxidation reduction reactions the cell uses to capture energy when oxidizing fuel i..e. food] hop from one cluster to the next by quantum tunneling”

The clusters he is referring to are proteins containing iron that are critical in accepting and passing on electrons.

This electron tunneling, these reactions, are the foundation of life, as we know it anyway. It is the very basis of energy used in all cells on earth. Bacteria, plants, us.

In quantum tunneling particles kind of “cheat” an energy barrier to a chemical reaction by just going through the energy barrier or wall rather (metaphorically) than over it. That is, it pops through the wall where without QM it shouldn’t. To clarify: most chemical reactions need energy to get going. If an electron is involved, say, as is often the case, for example in the oxidation/reduction reactions critical to life (or for example when a photon stimulates a photoreceptor in the eye) the reaction only happens if there is enough energy to get it going, to kick start it. But this can be skirted a bit by the uncertainty, the indeterminacy of QM that allows the electron (or photon) to be in unusual or unexpected states of being. By classical chemistry and physics, that shouldn’t happen, making the reactions much less likely, if they would happen at all, under normal circumstances.

That is, no QM tunneling, little or no passing of electrons from protein-iron complex to another, no usable energy for living things on earth.

By the way, we do use only a light bulb’s worth of wattage of energy to power our entire body, as Bob Lanza points out in “Biocentrism”. But still,  that is 10,000 times more energy per pound than the sun puts out! That’s because the sun is mostly just a big old ball of gas molecules just bouncing around at any one moment not putting out any energy (just being pushed around by the energy released by the nuclear reactions at the center of the sun). On the other hand, all living cells are prodigiously generating and using energy just to stay intact. The way cells store energy is in bonds between phosphate groups in ATP (adenosine tri phosphate) molecules, and a single cell goes through 10 million ATP molecules per second on average.

At its core life is quantum tunneling. It’s all energy.

Very Zen.

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