Science Nobel Prize round-up

Katarzyna Siewierska outlines the winners of the Nobel Prizes in physics, chemistry and physiology or medicine


Nobel Prize in Physics

Awarded to Takaaki Kajita and Arthur B. McDonald “for the discovery of neutrino oscillations, which shows that neutrinos have mass”. Neutrinos are particles with extremely tiny mass produced in nuclear reactions. There are trillions of neutrinos that were produced in the sun passing through your body every second. We don’t feel this because these particles are so small we are transparent to them. Neutrinos were first proposed in 1930 by Wolfgang Pauli, and were first experimentally detected in 1942. This achievement won the Nobel Prize in 1995. There are three different types, or flavours, of neutrinos: electron, tau and muon. In 1960s scientists had a problem came across a big problem. It seemed that the expected number of electron neutrinos coming from the sun and reaching Earth was too big, compared with the actual measurements. This was resolved 30 years later by assuming that neutrinos have a mass and hence can undergo neutrino oscillation. This means that it is possible for the electron neutrino to change into another flavour that could not be detected at the time. Takaai Kajita and Arthur B. McDonald lead two independent research teams, which found that when the electron neutrinos hit the atmosphere of the Earth they begin oscillating between flavours before hitting the detector. This discovery led to new understanding of neutrino physics and the modification of the standard model of particle physics.

Nobel Prize in Chemistry

The prize was awarded to Tomas Lindahl,  Paul Modrich and Aziz Sancar “for mechanistic studies of DNA repair”. Not many know that our cells have a special toolbox to fix errors in DNA that may occur after replication. There is no way that life could have developed based on such a fragile molecule like DNA without the cell being equipped with a sophisticated repair mechanism that will make sure that everything is in order. The research carried out by Tomas Lindahl demonstrated that the DNA molecule is a very unstable molecule and that without a mechanism to fix it, it would quickly decay. He discovered excision repair, which is a process that involves enzymes that eliminate errors and prevent mutations in the DNA. Most errors in the DNA occur every time the cell replicates and Paul Modrich elucidated how the cells correct those mismatches in the base pairs. This mismatch repair fixes about 99.9 percent of the errors that take place. Other errors can be caused by UV light and Aziz Sancar figured out how the cell fixes such errors. In these cases the process is called nucleotide excision repair. This is when enzymes remove the broken piece of the DNA and a piece with a correct sequence takes its place. The work of the three Nobel laureates of this year exposed the vulnerability of the DNA molecule and inspired others to study DNA repair.

Nobel Prize in Physiology or Medicine

The prize was awarded to William C. Campbell (¼), Satoshi Ōmura (¼) and Youyou Tu (½) “ for their discoveries concerning a novel therapy against infections caused by roundworm parasites” and the other half to Youyou Tu “for her discoveries concerning a novel therapy against Malaria.”