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Does Quantum Mechanics cause Gene mutation? Scientists have some evidence.

2025-01-18 Update From: SLTechnology News&Howtos shulou NAV: SLTechnology News&Howtos > IT Information >

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Cancer makes people change color, and quantum mechanics is a hot research field. The combination of cancer and quantum mechanics can easily lead to the association of exaggeration and grandstanding.

But some scholars have pointed out that quantum mechanics may be the DNA mutation, leading to the replication of the wrong physical principles, they also got some evidence. Let's see what's going on.

Photo: chemists of the getty21 century generally agree that quantum mechanics has a central place in chemistry. For example, quantum coherence and quantum entanglement determine the form of covalent bonds. And chemistry is the basis of biochemical processes, so it is not difficult to imagine that quantum mechanics is also the foundation of biochemical reactions.

However, as the molecules get larger and larger, quantum coherence becomes difficult to maintain, so most biochemical processes do not need to be explained by physics, but with the classical bat model.

Photo: 20 years ago, pixabay tried to use quantum mechanics to explain biological processes, which was ridiculed in both physics and biology. Most scholars at that time believed that quantum mechanics was useful at the micro level and negligible in the macro world, such as the biological world.

It is reasonable for them to look at it this way. For example, in the microscopic world, particles have a certain chance of "passing through the wall", which is called quantum tunneling.

Although living things are also made up of particles, when the number of particles increases, the possibility of passing through the wall decreases, so it is impossible for us to see anything that can penetrate the wall in our daily life.

Jim Al-Khalili, a physicist at the University of Surrey in the UK, recalled: "the seniors of physics told me not to touch this direction. They thought it was crazy."

However, in the past 20 years, researchers have discovered the important role of quantum mechanics in some biological processes, especially to solve a big problem in biology-the efficiency of photosynthesis.

Photo Source: pixabay in photosynthesis, photosensitive molecules that absorb photons, such as chlorophyll, are called chromophores. The chromophore absorbs photons of a specific wavelength, in which a small number of photons' energy is converted into heat, that is, the vibration of molecules, while most of them become excitons, an energy packet similar to particles.

In traditional theory, excitons (red) transferred between chlorophyll chromophores (green) go step by step to the reaction center (orange). Photo Source: LUCY READING-IKKANDA

The exciton energy packet must be transmitted to a centralized processing station, the photosynthetic reaction center, before it can be used for life activities. However, the chromophore aggregates into an array similar to the solar panel, the antenna pigment (pictured above), and the excitons produced by one chromophore need to pass through other chromophores to reach the photosynthetic reaction center.

According to the traditional biological theory, the transfer of excitons between chromophores is like random drumming, from one chromophore to another until finally reaching the center of photosynthetic reaction. This process is called F ö rster coupling.

But the problem is that excitons have to go through hundreds of chromophores to reach their destination, and every time they change hands, they lose energy. In other words, the more people go the wrong way, the lower the efficiency of photosynthesis. If the energy transfer process of photosynthesis is really like this, then its theoretical efficiency is only 50%.

However, the efficiency of photosynthesis is 95%, which exceeds the efficiency of other known human energy conversion, and occurs very quickly, which is a contradiction that can not be explained by traditional theory.

Graham Fleming, a physicist at the Lawrence Berkeley National Laboratory at the University of California, Berkeley, refutes the traditional model: "the classical jump model is incorrect and inadequate, it describes the real process incorrectly, and lacks an explanation for the unparalleled efficiency of photosynthesis."

But for a long time, it was thought that there was nothing wrong with quantum mechanics in this process. But in 2007, that view was broken. Fleming's team used Chlorobium tepidium, a green sulfur bacterium that can carry out photosynthesis, to find that exciton transport actually takes advantage of quantum coherence.

Image source: britannica originally, excitons have wave-particle duality, which is similar to a ripple that spreads in all directions. It can simultaneously explore various channels in the pond, that is, antenna pigments, and find the most effective way to get to the photosynthetic reaction center.

In quantum theory, excitons can calculate various paths at the same time to find the most efficient one to reach the photosynthetic reaction center (orange). Photo Source: LUCY READING-IKKANDA

"Quantum coherence plays an important role in the energy transfer of photosynthesis, revealing the efficiency of energy transfer," Fleming explained. (excitons) can search all energy transmission channels at the same time to find the most efficient one. "

In 2010, Gregory Scholes, a chemical researcher at the University of Toronto, and colleagues found that Cryptophyta algae in the ocean had similar quantum coherence.

In this way, in a short period of 20 years, the term quantum biology was coined and became a thriving branch of discipline. Researchers have also found more and more biological phenomena that cannot be explained by traditional theories but can be explained by quantum mechanics, such as the catalytic efficiency of enzymes, the mechanism of smell, and how birds feel about the Earth's magnetic field.

The Eurasian robin (Erithacus rubecula) can feel the earth's magnetic field, but cannot distinguish between the north and the south. This phenomenon is difficult to explain by classical theory, but it can be explained by quantum mechanics. Photo Source: pixabay

One of the important problems that can be explained by quantum mechanics is DNA mutation.

DNA's double helix structure is similar to a rotating ladder, each "step" of the ladder is actually a hydrogen bond. A hydrogen bond is actually a proton that connects the left and right bases, and this proton is usually slightly closer to one side of the step.

Pictures of hydrogen bonds and bases (AGCT) on DNA Source: in harvard.edu1963, Swedish physicist Per-Olov L ö wdin, a member of the Nobel Physics Committee, put forward a theoretical hypothesis in an article published in Reviews of Modern Physics: in the process of DNA replication, the proton on the hydrogen bond may be in some quantum state if the proton is near the wrong side of the "step". Then the DNA will mutate, and the error of protons can be realized by quantum tunneling.

Specifically, during DNA replication, hydrogen bonds between bases are broken and can be combined with new nucleotides. Normally, base A (adenine) binds to T (thymine) and C (cytosine) binds to G (guanine).

However, nucleotides may change as a result of proton tunneling, and A will become A, A will become T, and T will become T *. This misbehavior of protons that worries Leftin is called tautomerization (tautomerization).

The normal Amurt base pair (top) and the tautomeric Amur murt T * base pair (bottom). Source: (DOI) 10.1039 / C5CP00472A

Despite the fact that you just wear a flower on your head, the temperament of the whole base will change. Unlike A, A* does not want to combine with the real object T, but is more likely to combine with the object C of G. And T* does not like A, it is easier to combine with G, the whole mess stew, which will lead to mutation.

Does Leftin's idea make sense? Thirty years later, some circumstantial evidence emerged.

In the past, biologists were generally taught that mutations should occur randomly, so the probabilities of mutations should be about the same, as Richard Dawkins pointed out in his book Blind watchmaker (The Blind Watchmaker), evolution is blind (evolution is blind).

But in 1988, John Cairns, a biologist at Harvard University, and his colleagues discovered a strange phenomenon that did not conform to the traditional theory of evolution: E. coli (E. coli) can quickly obtain favorable mutations.

They put E. coli that cannot digest lactose in a petri dish with only lactose. As a result, these Escherichia coli have a mutation that can digest lactose, and this mutation occurs much faster than the theory expected, that is, the mutation occurs randomly. Their study was published on Nature.

Source: wikimedia to explain this strange mutation in E. coli, Johnjoe McFadden, a biologist at the University of Surrey in the UK, thought it might have something to do with quantum mechanics. So he began to turn to scholars in the physics department of the university for help. Al-Khalili was very interested in McFadden's view, so the two began to work together.

Using Leftin's theory, Al-Khalili and McFadden proposed that, in fact, the protons on the hydrogen bond of DNA were in a superposition state before the observation, meaning that it was not sure whether it would fall to the side of the mutation or the side without the mutation.

Photo Source: getty takes E. coli, which does not eat lactose, as an example. Before lactose is encountered, E. coli is in a superposition state where it is possible to digest lactose or unable to digest lactose. Al-Khalili and McFadden then calculated that the presence of lactose molecules caused the state of protons to collapse in a way that could digest lactose, which explains why E. coli mutates faster than expected in classical theory.

Encouraged by these studies, some ambitious researchers believe that quantum mechanics will be a breakthrough in conquering cancer. In 2013, Frank Trixler, a chemist at the University of Munich, even suggested that proton tunneling on the hydrogen bond of DNA was the origin of species evolution.

Photo Source: wikimedia

However, there is still considerable controversy in academic circles as to whether the quantum world dominates some basic biological processes. Quantum biology needs more evidence to support these big and beautiful hypotheses.

Before the answer is revealed, let's enjoy the wonderful waiting superimposed by expectation and doubt for a while.

Often feel out of place with the environment because they are not perverted enough? Maybe your DNA hasn't learned quantum tunneling yet.

The reference materials are stored in graphite:

Https://shimo.im/docs/CC3jxTV6TJcwRtPt/

This article comes from the official Wechat account: take Science Home (ID:steamforkids), author: Qijun

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