What is quantum biology, the branch of science that can reveal why we are alive

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If we took a few minutes to think about what quantum physics is, what would you say?

Many people might answer that they are complicated formulas that explain very complex processes related to subatomic particles, gravity, energy, the movement of galaxies, black holes and everything that has to do with space-time and the size of the universe.

Something more or less like the ideas of Albert Einstein. But that wouldn’t be a far cry from reality.

After all, the father of the Theory of Relativity laid the foundations for statistical physics and quantum mechanics, part of modern physics that is very different from that raised by Isaac Newton centuries ago.

But there is a less explored branch that does not oblige us to go very far to understand what it is about. In fact, it is here, on our planet, among us.

Iraqi-British theoretical physicist Jim Al Khalili raised the question in 2015 with a question during a lecture: “What if the quantum world played an important role in the functioning of a living cell?”

Can something so small help us understand why we are alive?

For many years, the scientific community was straightforward: biology was such a complex science that it had nothing to do with the quantum world.

Today, this idea is seen as wrong. In fact, quantum mechanics plays such an important role in biological processes that it is vital for plant photosynthesis or cellular respiration.

This branch of science is known as quantum biology.

And understanding it would open the door to countless answers and processes that we still don’t fully understand, from understanding how mutations work to creating new drugs or improvements in quantum computing.

“In a way we are solving an important mystery,” said Vladimiro Mujica, a chemist at the Universidad Central de Venezuela and a PhD in Quantum Chemistry from the University of Uppsala in Sweden.

Recently, Arizona State University in the United States, where Mujica currently works, received a $1 million grant from the Keck Foundation in conjunction with the University of California at Los Angeles and Northwestern University in Chicago. The goal is to study quantum biology for the next three years.

The idea is to fully understand the scope of this branch, which is revolutionizing the way we understand the relationship between quantum processes and life itself.

But what is quantum biology?

To answer the question, let’s start with quantum mechanics:

Modern physics is mainly based on two branches that study relativity and the quantum world. The first studies fields such as the movement of galaxies and planets; the second tries to explain the atomic and subatomic systems that are so small that we cannot see them with the naked eye.

A giant world and a small world.

The obvious side is that chemistry, biology and biochemistry are part of this universe. And that matter is made up of atoms and molecules.

So if quantum physics studies this atomic world, it would also be describing biology, right?

“Biological processes are actually quantum systems because (quantum) physics describes the behavior of matter at the microscopic level”, explains Mujica to BBC News Mundo, the BBC’s Spanish service.

This is a conclusion that seems very simple. But it wasn’t always so obvious.

And there’s a compelling reason: biological processes are really very complex. On the other hand, quantum systems need “stability”, something scientists know as wave coherence.

The conclusion of the scientific community is that biological processes were so “noisy” that they lacked this stability. Basically, they destroyed coherence.

That’s why, throughout the 20th century, scientists separated quantum mechanics from biology. They didn’t give much interest to the topic.

But maybe something was missing that the scientists didn’t quite understand or that didn’t quite fit. Perhaps there was a method where all this was applied within biological processes.

‘non-trivial’

It is already known that matter is composed of particles. Some are protons and neutrons, and others are known as elementary particles, like electrons and photons.

These particles work on the biological level. For example, photosynthesis in plants is driven by the transfer of electrons in molecules.

But there is a problem here: how does this electron travel? If we had a light bulb, the electron would pass through a copper wire which gets very hot and causes the light to “turn on”.

But plants don’t have copper wire. In fact, biology has “terrible” conductors of energy, in Mujica’s words, and abruptly raising the temperature would cause the cell to simply die.

So the electron would need that thing that scientists didn’t understand. A process that was simple and didn’t require a lot of energy to allow the particle to travel without killing the cell.

This process actually exists and is called tunneling.

An example: if we have a tennis ball on one side of a court and we have to pass it to the other side, it would be enough to throw it from one end to the other.

But if the court had a very high wall in the middle, then the ball would have to be thrown very high and over the wall — otherwise it would hit the wall. That’s how classical physics works.

But it’s different in quantum physics. If the tennis ball were really an electron, there is a way for the electron to pass through the wall and not over it. And this happens because the particles move in the form of waves.

The tunnel effect is like “punching a hole in the wall and walking through it”. And the advantage is that this process is so simple and effective that it is used by biological systems to use the least amount of energy possible.

Scientists call these types of events “non-trivial.” It’s basically how quantum mechanics alters biological processes.

It is not something new, however. Physicists such as the Austrian Erwin Schrödinger had already tackled this and other topics in quantum physics in the first half of the 20th century, laying the groundwork for other scientists to make new discoveries.

different processes

But the tunnel effect is not the only quantum mechanism at work within biological processes.

There are others, such as the direction in which the particle rotates, something known as spin. And all these effects act in different ways at different stages of biological processes.

For example, photosynthesis consists of three steps. The first is the capture of the photon (the particle carrying electromagnetic radiation, such as sunlight) by the plant.

The second is when the electrons absorb the energy of the photons and move to a higher energy state, traveling through the molecules and based on the tunnel effect.

Finally, the electron is used for a chemical reaction that results in the release of oxygen. And that’s what allows animals and humans to breathe.

In all these stages, quantum mechanics is present.

But now imagine that the electron is rotating on its own axis (spin), and this movement can be to the right or to the left. Depending on the direction of spinthe electron will or will not pass through the tunnel.

For simplicity, think of it as a screw, which when inserted into the hole can only be screwed in the right direction. But if you try any other way, it doesn’t happen or you damage it.

This is what is known as chirality, from the Greek kheir, which means hand. When an object is chiral, there is another that is its reflection, like the right hand with the left.

This means that the spin goes hand in hand with chiral.

“So now you have a privileged mechanism that protects the transport from any external noise. Therefore, an effect that was not meant to be important now is”, summarizes Mujica.

Understanding this process is very important for science. It is now known that tunneling, spin and chirality are related not only to photosynthesis, but also to protein synthesis, the way organisms breathe, or the connection between neurons.

Even in mutations, transformations of genetic material that occur by the random change of a molecule in our body.

different applications

But what is all this for? Would it have any use in visible world applications?

For now, scientists are just trying to understand the true dimension of quantum biology. After all, for a long time it was considered unimportant. It’s been about a decade since this field of science started to emerge again.

One branch that could benefit is pharmacology, where chirality plays an important role.

Another is quantum computing. “At the point where we are, we are going to try to find good systems to do quantum processing,” says Mujica. “Quantum computers already exist, but they are very limited. They are very advanced and extremely expensive toys,” he adds.

What is now evident is the crucial role that quantum physics plays in helping us understand how the very important biological processes that make life possible work.

So it’s not so much about looking for other planets, but also about taking a deep look at ourselves.

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