Glossary

Apoptosis is a method used by the body to dispose of unwanted or abnormal cells. It is sometimes called ‘programmed’ cell death, because the cell’s contents are carefully broken down for collection and reuse by the immune system.

Biophotons are infrared-to-ultraviolet emissions from biological material. They are often called ultraweak emissions due to the comparably low number of photons emitted. They appear to be associated with stressed metabolic states and the balance of reactive oxygen species (ROS).

The cell cycle is the series of changes that take place in a cell as it grows and divides. The cycle is essential for the growth, reproduction and repair of living organisms such as humans. For example, without the cell cycle, our bodies would not be able to repair damage caused by injury or illness.

Cells will move towards chemicals they find attractive - glucose, for example - and away from toxins. When they move towards attractant chemicals or away from repellents, the process is known as chemotaxis. Virtually every organism that is capable of movement exhibits some type of chemotaxis.

A chromophore is a light-sensitive molecule that absorbs and emits light at various specific wavelengths. This light sensitivity is due to their molecular structure. It is thought that chromophores in biology emerged from the need to dissipate or channel the energy of absorbed sunlight, particularly the high-energy and potentially damaging ultraviolet rays.

Clinical trials on new drugs are conducted in stages called ‘Phases’. At each Phase, the drug developer has to satisfy strict criteria set by the medical regulators. These criteria are grouped under three headings – quality, safety and efficacy. Quality refers to the way in which the drug is manufactured – for example, does every tablet contain exactly the same components? Safety is concerned with any possible side effects patients may suffer and how severe they are. Efficacy is the measure of how well the drug treats the condition for which it is indicated.

In Phase I trials, researchers test the drug on a small group for the very first time. They are usually healthy volunteers. The aim at the outset is to learn about safety and identify any unwanted side effects.

When the process moves on to Phase II, the drug is given to a larger group of people (usually more than 100) to determine whether it is effective.

Phase III trials are much larger in scale and may involve several thousand people. A considerable body of data has to be collected to confirm the drug’s effectiveness, compare it with other treatments and persuade the regulator that it can be authorised for public use.

Coherence is an integral concept in quantum biology. It quantifies the degree to which quantum systems preserve observable properties such as superposition and entanglement. Its opposite, decoherence, describes the loss of these effects, which can be brought about when a quantum system interacts with its (much larger) surrounding environment.

Cytoplasm is a gel-like fluid found inside a cell. It is inside the body of the cell but outside the nucleus. Because it acts as a medium for chemical reactions, all the vital functions for cell expansion, growth and replication are carried out in the cytoplasm.

A dissipative system is one that is open and is not in a state of equilibrium. It exchanges energy, matter and information with its environment. Hurricanes and human society are both dissipative systems. At the Guy Foundation, we contend that life itself is also a dissipative system.

DNA (deoxyribonucleic acid) is a molecule found in almost all organisms – including humans. It contains the instructions for the organism’s development, functioning, growth and reproduction. DNA is stored in the nucleus of a cell, distributed among long structures called chromosomes. Each chromosome is composed of thousands of shorter segments of DNA, called genes. DNA is famously arranged in two strands, which are intertwined in the shape of a double helix.

An electrochemical gradient, or membrane potential, is a difference in proton or ion concentration across a biological membrane. It results in an electric voltage potential that charged particles experience as a force. This membrane potential is achieved in various ways, including through electron transport chains (ETCs), proton pumps such as ATPase or ion channels.

Electromagnetism is the branch of physics that deals with interactions between charged particles with electric and magnetic fields, and their field unification as light. These interactions are mediated by photons, which manifest the particulate nature of the electromagnetic wave.

Inside each mitochondrion is an electron transport chain (ETC). The ETC allows us to extract energy efficiently from our food in the presence of oxygen. It is responsible for releasing the units of energy which are distributed around our cells.

Entanglement is the strongest form of quantum correlation. Schrödinger described it as ‘the characteristic trait of quantum mechanics, the one that enforces its entire departure from classical lines of thought’. It describes an inseparable whole quantum state, each of whose sub-systems cannot be described independently of the state of any other, no matter how far apart they may be. A change induced in one will immediately affect the other.

Entanglement has been used as a resource in cryptography for secure communication. In biological systems, entanglement might play a role in information processing and transmission. It could also contribute to more efficient, super-resolution imaging.

Envirogenetics is the combination of environment and genetics. It is the study of the ways in which factors in our external environment such as geography, diet and lifestyle influence our internal environment – our genetics, our physiology and our behaviour. The envirogenetic envelope is the particular combination of all those factors acting on an individual.

Epigenetics is the study of how behaviour and environment can affect gene functioning. Epigenetic changes can be reversed and they do not change the DNA sequence within an organism. But they can modify the way in which the organism reads a particular sequence.

The Epstein–Barr virus (EBV), one of the most common viruses in humans, is best known as the cause of glandular fever. It is also associated with diseases such as Hodgkin’s lymphoma and rheumatoid arthritis and may be a cause of multiple sclerosis. Like Covid, EBV induces chronic fatigue syndrome. It can alter mitochondrial dynamics, hamper the replication of DNA and impair our anti-virus early-warning systems.

A Faraday cage is a form of container that blocks electromagnetic waves. It is named after the nineteenth-century British physicist Michael Faraday, who discovered magnetic induction – the principle which lies at the heart of electric motors.

The cage works because when an electromagnetic field hits something that conducts electricity, it does not pass through. A microwave is a form of a Faraday cage, since it keeps microwaves trapped inside the machine as it heats the food, while hospitals with MRI scanners use Faraday cages to shield the equipment from radio signals.

In mathematics, a fractal is a shape that is infinitely complex. But while the pattern repeats forever, every individual part looks similar to the whole image.

The shapes do not have to be identical; the main requirement for being fractal is that they display inherent and repeating similarities.

Mathematical fractals are formed by calculating a simple equation many times over and feeding the answer back to the start. Natural fractals include patterns that branch, such as trees, rivers and blood vessels. A British engineer, David Smith, has discovered a thirteen-sided geometrical shape that can fill any space without gaps or repetition.

A gap junction is essentially a bridge between two cells. Gap junctions are made up of specialised proteins. They appear in virtually all the tissues of the body, and they allow molecules, ions and – crucially – electrical impulses – to pass across the gap between the interlinked cells.

Homeostasis is the ability of cells, tissues, and organisms to keep living systems in their optimal state. It involves the constant adjustment of variables such as temperature and glucose levels to maintain a stable internal environment.

Hormesis is the name given to the long-observed biological phenomenon whereby moderate exposure to a ‘stressor’ induces an organism to change in a manner that makes it more resistant. Mitochondria play a key role in hormesis.

Inflammageing is accelerated ageing caused by inflammation. If the normal functioning of a mitochondrion and the other cell components it interacts with begins to be disturbed, the result is increased cellular inflammation. The more inflamed the cell becomes, the more difficult it is to sustain appropriate mitochondrial function. It’s a vicious feedback circle that leads to other processes that mimic what happens in later life.

In his ‘Light and Life’ talk, Niels Bohr addressed one of the fundamental problems facing researchers into quantum physics at that time: particles do not look like waves and waves do not look like particles.

Bohr’s solution was that particles and waves both exist and both can be employed when interpreting the quantum world. In a particular experiment you might observe one or the other, but you will never observe both. This is not a contradiction, he said; the two forms are complementary to one another.

The microbiome is a community of microorganisms living together. In mammals, it is located within the gut. The bacteria in the microbiome aid digestion and help protect against disease.

Microtubules are narrow, hollow, tube-like structures found in the fluid inside the cells of plants and animals. They help support the shapes of the cells and play a particularly important role in the functioning of neurons, which use microtubules as highways to transport materials such as mitochondria along the length of their axon.

Neurons are made up of three main elements: the cell body; dendrites, which receive incoming signals; and the axon, which transmits them.

Signals pass between nerves where the axon of one nerve cell meets the dendrites of another. This point is known as the synaptic cleft.

P. polycephalum is a sticky, yellow mould that lives on decaying leaves and logs. Initially, it exists as a single-celled organism. But each cell can merge with others to form a super-cell as much as a metre in length. Not only can slime mould seek out food such as fungal spores, but in laboratory settings it has successfully escaped from a trap and found its way around a maze.

Light was classically described as an electromagnetic wave. But Einstein suggested that, in addition to behaving like a wave, light also comes in discrete packets. It behaves as a particle with a minimum ‘quantum’ of energy. These particles of light came to be named photons.

Brain plasticity provides the basis for our normal brain functions, such as our ability to learn or change our behaviour. It is strongest during our childhood, but it remains an important property of our brain throughout our lives.

Quantum literally means ‘how much’. It is used to describe the minimum unit of energy or matter. The German physicist Max Planck realised that there was a minimal ‘quantum of action’, in effect a minimum change that can be measured in nature. The term was used in 1905 by Albert Einstein who proposed that a beam of light is not a single wave flowing through space like the tide flowing towards a shoreline, but rather a collection of separate packets of energy, which he called ‘light quantums’. The energy takes the form of electromagnetic radiation and the packets have become known as photons.

A quantum state refers to a particular property of a quantum system. It might be the energy, the position, the spin or something else. For two quantum states, a linear combination of their states also describes the system. This is known as superposition, made famous by the ‘Schrödinger’s cat’ thought experiment.

Quantum theory is concerned with matter and energy at the atomic and subatomic level. It describes the nature of entities such as atoms, electrons, protons and photons. Central to the theory is ‘wave–particle duality’, where light and matter can behave both as a wave and as a particle.

Quinine has a long medical history. In the 1640s, the governor’s wife in a province of Peru caught malaria and was treated by the local Indians using an extract from cinchona bark. The Jesuits in Peru saw its potential and established trade routes to distribute the bark throughout Europe. A few years later, Oliver Cromwell died from malaria because he refused to take the same Jesuit bark. In 1822, quinine became the first chemical medicine to be synthesised.

The quantum property of spin plays a role in chemical reactions, where electrons that occupy the same orbitals must have opposite spin states. It involves absorption of a photon by a bound electron, resulting in a spatially separated but spin-correlated pair, known as a radical pair. Interaction with the electrons’ physical surroundings, including the Earth’s magnetic field, causes the resulting quantum state to oscillate configuration between ‘singlet’ and ‘triplet’ states, where singlet and triplet indicate a different relative orientation of the two spins. These spin states determine biochemical outcomes, which can in principle be sensed by the organism.

Reactive oxygen species (ROS) are highly reactive chemicals formed from oxygen atoms during the process of breathing. ROS play a role in signalling between cells and also in maintaining homeostasis.

However, they can also cause irreversible damage to DNA, as they prevent some cells from performing their original functions.

The body also generates reactive nitrogen species (RNS), which can contribute to harmful circulatory conditions.

Redox is a chemical reaction in which the oxidation states of atoms are changed. Usually, the chemical species undergoing oxidation loses electrons, while the one undergoing reduction gains electrons.

RNA (ribonucleic acid) is a messenger molecule carrying the instructions from DNA. Unlike DNA, it is formed only from one single strand. While DNA is self-replicating, RNA cannot replicate on its own.

An ROS scavenger removes ROS and protects cells from the inflammation caused by oxidative stress. ROS scavengers are composed of naturally occurring polymers – substances with very large molecules that are built up from many identical subunits.

Erwin Schrödinger (1887–1961) was a Nobel Prize-winning Austrian scientist who developed many of the key concepts in quantum theory. Schrödinger postulated that if you placed a cat in a sealed box with something that could potentially kill it, such as a radioactive atom in a quantum superposition, you could not know if the cat was dead or alive until you opened the box. From your perspective as an observer, the cat was both dead and alive until such time as the box was opened.

Spin is not due to any spinning motion of the particles in question. It is an intrinsic quantum property. It describes how quantum systems such as electrons and protons will respond to a magnetic field. It also plays a role in chemical reactions, where electrons that occupy the same orbitals must have opposite spin states. Spin also dictates the magnetic properties of certain materials, for instance paramagnetic materials which have unpaired spins, and diamagnetic materials where all the spins are paired.

Stem cells are the body’s basic building blocks. They are the raw materials from which other cells are generated to perform various functions in the body. Under the right conditions, stem cells can be made to divide and form what are known as daughter cells. Stem cell therapy uses stem cells to repair diseased or damaged tissue. It is seen as the next big step in organ transplantation because it uses cells rather than donated organs.

Superposition is the ability of a quantum system to be in many states simultaneously until such time as it is measured. It is often characterised as a quantum switch or bit, being both ‘on’ and ‘off’ at the same time.

The term synchrony is used in different branches of science, from mathematics to oceanography, to describe the way in which two or more things happen at the same time or speed. It may be a pattern such as tidal rhythm, animal mating behaviour or a group of musicians playing together. It can also refer to the precise moment in time an event takes place, such as two photons arriving together at the same point.

The internationally accepted unit of measurement for the intensity of a magnetic field is the tesla (T). It is named in honour of the physicist, electrical engineer and inventor, Nikola Tesla. A medical MRI scanner has a field strength of between 1.5T and 3T, while the magnetic field strength required to levitate a frog would be about 16T. The Earth’s natural magnetic field is about 30 to 40 millionths of a tesla (microteslas or μT).

Thermodynamics is the branch of physics that deals with temperature, heat, work, energy and entropy. As a discipline, it was advanced considerably by the invention and refinement of the steam engine. Thermodynamics is now essential to our understanding of chemical and biological systems, both in and out of equilibrium. Thermodynamics has also been expanded to include ideas around information for classical and quantum systems, and the energy costs of their manipulation for computing tasks.

The phenomenon of tunnelling follows from quantum systems’ wave–particle duality and describes how particles can penetrate classically forbidden energy barriers. The likelihood of tunnelling depends on the particle’s energy and mass, and the size of the barrier. Tunnelling is more likely for very light particles like electrons and protons, but less so for heavier objects.

Electrons leaking from the ETC can cause the formation of potentially harmful reactive oxygen species. One way in which this can be mitigated is through uncoupling, which allows proton leak through the membrane without ATP production. Uncoupling is controlled by several different types of protein and is a key mechanism in homeostasis and signalling.

Viscosity measures a fluid’s resistance to flow. The higher its viscosity, the more slowly a liquid will flow. Syrup and honey, which have high viscosities, are sticky and do not flow easily. Water and alcohol have much lower viscosities and flow much more freely.