Written by Jasmine Mace
A piece on quantum biology by Jasmine Mace submitted to the New York Times Learning Network.
Scaling the DNA double-helix is no simple feat– one must navigate twists and turns of molecular mayhem where exists a winding ladder of phosphate groups, sugars, and nucleotide bases. As if connecting the ladder split into two vertical stalks, nucleotide bases (the molecular building blocks of DNA) on each side are paired with their complement: adenine with thymine and guanine with cytosine. Like assembling puzzle pieces, this ladder of life is responsible for every function in our bodies, and the mismatching of these pieces (i.e. mutations) can result in rather malignant effects. For decades, scientists have sought cures to mitigate or extinguish the harmful outcomes of DNA mutations, which have been found to cause cancer by rendering growth-regulating proteins dysfunctional. Here enters our unlikely champion: quantum physics.
Quantum theory attempts to describe physics at the subatomic level. It brought about the field of study called quantum biology, which fuses the disciplines of quantum mechanics and biology to examine the underlying principles of biological phenomena. The two fields join forces to attack unsolved enigmas such as how birds use Earth’s magnetic field, how photons interact with plants to produce chemical energy, and how DNA mutates. As Persiana Saffari of Stanford University put it: “By first understanding the mechanism of how mutation occurs, scientists believe that they can crack the code on why our DNA may be susceptible to such random mutations and, subsequently, genetic disease.”
In the quantum realm, matter acts heretically to the classical laws of physics taught in school: it can spin in both directions simultaneously, exist in two places at once, and behave in unison with an entangled particle millions of light years away. Do physicists fully understand how this works? No. Do some still attempt using it to describe life’s most fundamental molecule? Absolutely.
Theoretical physicists Jim Al-Khalili, A.D. Godbeer, and Paul Stevenson investigated the role of a quantum singularity called tunneling in adenine-thymine base pairs, which are “glued” together by hydrogen bonds down the vertical cross-section of DNA. Tunneling, characterized by the breaking of an energy barrier by a particle, allows matter to “magically” appear on the other side of, without physically jumping over, a barrier. The study found that through proton tunneling, “a hydrogen atom can ‘jump' from one place to another within a molecule,” says Al-Khalili. It concluded that hydrogen protons can penetrate a force field separating two base pairs and alter the energetic affinity of those bases as to bind them with their non-complementary counterparts. Simply put, quantum tunneling may be responsible for point mutations in DNA.
Al-Khalili, Godbeer, and Stevenson aptly note that “even if quantum tunneling… does not play an important role in point mutations in DNA, there is still the potential for utilising the tools developed here in other biochemical processes, such as those involving proton transfer promoted by enzyme catalysis.” Thus, if well-founded, this model can operate at the frontier of cancer research and oncological technology. Quantum biology may revolutionize society’s understanding of life science, medicine, and public health.
Sources
https://ghr.nlm.nih.gov/primer/mutationsanddisorders/mutationscausedisease
https://www.discovermagazine.com/the-sciences/solving-biologys-mysteries-using-quantum-mechanics
Modelling proton tunnelling in the adenine–thymine base pair Godbeer, A.. Physical chemistry chemical physics : PCCP Volume: 17 Issue 19 (2015) ISSN: 1463-9076 Online ISSN: 1463-9084.
https://pubs.rsc.org/en/content/articlelanding/2015/CP/C5CP00472A#!divAbstract
https://www.nytimes.com/2019/09/07/opinion/sunday/quantum-physics.html