Alkane

ˈalkeɪn/

any of the series of saturated hydrocarbons including methane, ethane, propane, and higher members

Alkene

ˈalkiːn/

any of the series of unsaturated hydrocarbons containing a double bond, including ethylene and propene

Alkyne

ˈalkʌɪn/

any of the series of unsaturated hydrocarbons containing a triple bond, including acetylene

Alveolus

ˌalvɪˈəʊləs,alˈvɪələs/

any of the many tiny air sacs of the lungs which allow for rapid gaseous exchange.

Amplitude

ˈamplɪtjuːd/

the maximum extent of a vibration or oscillation, measured from the position of equilibrium.

Analysis

əˈnalɪsɪs/

detailed examination of the elements or structure of something.

Ancillary

anˈsɪləri/

providing necessary support to the primary activities or operation of an organization, system, etc.

Angstrom

ˈaŋstrəm/

a unit of length equal to one hundred-millionth of a centimetre, 10−10 metre, used mainly to express wavelengths and interatomic distances.

Anion

ˈanʌɪən/

a negatively charged ion, i.e. one that would be attracted to the anode in electrolysis.

Assumption

əˈsʌm(p)ʃ(ə)n/

a thing that is accepted as true or as certain to happen, without proof.

Borax

ˈbɔːraks/

a white compound which occurs as a mineral in some alkaline salt deposits and is used in making glass and ceramics, as a metallurgical flux, and as an antiseptic.

Beta

ˈbiːtə/

the second letter of the Greek alphabet ( Β, β ), transliterated as ‘b’, denoting the second of a series of items, categories, forms of a chemical compound, etc.

Buoyancy

ˈbɔɪənsi/

the ability or tendency of something to float in water or other fluid.

Beam

biːm/

a long, sturdy piece of squared timber or metal used to support the roof or floor of a building.

Buckling

ˈbʌklɪŋ/

a sudden failure of a structural member subjected to high compressive stress, where the actual compressive stress at the point of failure is less than the ultimate compressive stresses that the material is capable of withstanding.

Barometer

bəˈrɒmɪtə/

an instrument measuring atmospheric pressure, used especially in forecasting the weather and determining altitude.

Bioinformatics

ˌbʌɪəʊˌɪnfəˈmatɪks/

the science of collecting and analysing complex biological data such as genetic codes.

Bacterium

bakˈtɪərɪəm/

a member of a large group of unicellular microorganisms which have cell walls but lack organelles and an organized nucleus, including some which can cause disease.

Biochemical (adjective)

ˌbʌɪəʊˈkɛmɪk(ə)l/

relating to the chemical processes and substances which occur within living organisms.

Biodiversity

ˌbʌɪə(ʊ)dʌɪˈvəːsɪti/

the variety of plant and animal life in the world or in a particular habitat, a high level of which is usually considered to be important and desirable.

Catabolism

kəˈtabəlɪz(ə)m/

the breakdown of complex molecules in living organisms to form simpler ones, together with the release of energy; destructive metabolism.

Cytosol

ˈsʌɪtə(ʊ)sɒl/

the aqueous component of the cytoplasm of a cell, within which various organelles and particles are suspended.

Cytoskeleton

ˈsʌɪtəʊˌskɛlɪt(ə)n/

a microscopic network of protein filaments and tubules in the cytoplasm of many living cells, giving them shape and coherence.

Catalyst

ˈkat(ə)lɪst/

a substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change.Chromoplast

ˈkrəʊməplast,-plɑːst/

a coloured plastid other than a chloroplast, typically containing a yellow or orange pigment.

Criticism

ˈkrɪtɪsɪz(ə)m/

the expression of disapproval of someone or something on the basis of perceived faults or mistakes.

Cruise (verb)

kruːz/

sail about in an area without a precise destination, especially for pleasure.

Cation

ˈkatʌɪən/

a positively charged ion, i.e. one that would be attracted to the cathode in electrolysis.

Capacitance

kəˈpasɪt(ə)ns/

the ability of a system to store an electric charge.

Chromatography

ˌkrəʊməˈtɒgrəfi/

a technique for the separation of a mixture by passing it in solution or suspension through a medium in which the components move at different rates.

Delta

ˈdɛltə/

the fourth letter of the Greek alphabet ( Δ, δ ), transliterated as ‘d’.

Density

ˈdɛnsɪti/

the degree of compactness of a substance.

Distillation

ˌdɪstɪˈleɪʃn/

the action of purifying a liquid by a process of heating and cooling.

Dimension

dɪˈmɛnʃ(ə)n,dʌɪ-/

a measurable extent of a particular kind, such as length, breadth, depth, or height.

Displacement

dɪsˈpleɪsm(ə)nt/

the action of moving something from its place or position.

Dynamics

dʌɪˈnamɪks/

the branch of mechanics concerned with the motion of bodies under the action of forces.

Deficiency

dɪˈfɪʃ(ə)nsi/

a lack or shortage.

Dominance

ˈdɒmɪnəns/

the phenomenon whereby, in an individual containing two allelic forms of a gene, one is expressed to the exclusion of the other.

Differentiation

ˌdɪfərɛnʃɪˈeɪʃn/

the action or process of differentiating.

Distance

ˈdɪst(ə)ns/

the length of the space between two points.

Ellipse

ɪˈlɪps/

a regular oval shape, traced by a point moving in a plane so that the sum of its distances from two other points (the foci) is constant, or resulting when a cone is cut by an oblique plane which does not intersect the base.

Enzyme

ˈɛnzʌɪm/

a substance produced by a living organism which acts as a catalyst to bring about a specific biochemical reaction.

Electrophoresis

ɪˌlɛktrə(ʊ)fəˈriːsɪs/

the movement of charged particles in a fluid or gel under the influence of an electric field.

Electron

ɪˈlɛktrɒn/

a stable subatomic particle with a charge of negative electricity, found in all atoms and acting as the primary carrier of electricity in solids.

Elasticity

ɛlaˈstɪsɪti,iː-,ɪ-/

the ability of an object or material to resume its normal shape after being stretched or compressed; stretchiness.

Elastomerɪˈlastəmə/

a natural or synthetic polymer having elastic properties, e.g. rubber.

Energy

ˈɛnədʒi/

the strength and vitality required for sustained physical or mental activity.

Equilibrium

ˌiːkwɪˈlɪbrɪəm,ˌɛkwɪ-/

a state in which opposing forces or influences are balanced.

Event

ɪˈvɛnt/

A set of possible outcomes resulting from a particular experiment.

Electromagnetism

ɪˌlɛktrəʊˈmagnɪtɪz(ə)m/

the phenomenon of the interaction of electric currents or fields and magnetic fields.

Fructose

ˈfrʌktəʊz,-s/

a sugar of the hexose class found especially in honey and fruit.

Fluorescence

flʊəˈrɛs(ə)ns,flɔː-/

the visible or invisible radiation produced from certain substances as a result of incident radiation of a shorter wavelength such as X-rays or ultraviolet light.

Finite (adjective)

ˈfʌɪnʌɪt/

limited in size or extentFunction

ˈfʌŋ(k)ʃ(ə)n/

a relation or expression involving one or more variables.

Fullerene

ˈfʊləriːn/

a form of carbon having a large spheroidal molecule consisting of a hollow cage of sixty or more atoms, of which buckminsterfullerene was the first known example.

Force

fɔːs/

strength or energy as an attribute of physical action or movement.

Friction

ˈfrɪkʃ(ə)n/

the resistance that one surface or object encounters when moving over another.

Fluid

ˈfluːɪd/

a substance that has no fixed shape and yields easily to external pressure; a gas or (especially) a liquid.

Fusion

ˈfjuːʒ(ə)n/

the process or result of joining two or more things together to form a single entity.

Frequency

ˈfriːkw(ə)nsi/

the rate at which something occurs over a particular period of time or in a given sample.

Gene

dʒiːn/

a unit of heredity which is transferred from a parent to offspring and is held to determine some characteristic of the offspring.

Gas

gas/

an air-like fluid substance which expands freely to fill any space available, irrespective of its quantity.

Graphite

ˈgrafʌɪt/

a grey crystalline allotropic form of carbon which occurs as a mineral in some rocks and can be made from coke.

Geometry

dʒɪˈɒmɪtri/

the branch of mathematics concerned with the properties and relations of points, lines, surfaces, solids, and higher dimensional analogues.

Geocentric (adjective)

dʒiːə(ʊ)ˈsɛntrɪk/

having or representing the earth as the centre, as in former astronomical systems.

Geostationary (adjective)

dʒiːə(ʊ)ˈsteɪʃ(ə)n(ə)ri/

(of an artificial satellite of the earth) moving in a circular geosynchronous orbit in the plane of the equator, so that it appears to be stationary in the sky above a fixed point on the surface.

Gravity

ˈgravɪti/

the force that attracts a body towards the centre of the earth, or towards any other physical body having mass.

Genetics

dʒɪˈnɛtɪks/

the study of heredity and the variation of inherited characteristics.

Gill

gɪl/

the paired respiratory organ of fish and some amphibians, by which oxygen is extracted from water flowing over surfaces within or attached to the walls of the pharynx.

Glucose

ˈgluːkəʊs,-z/

a simple sugar which is an important energy source in living organisms and is a component of many carbohydrates.

Hydrogen

ˈhʌɪdrədʒ(ə)n/

a colourless, odourless, highly flammable gas, the chemical element of atomic number 1.

Halogen

ˈhalədʒ(ə)n,ˈheɪl-/

any of the elements fluorine, chlorine, bromine, iodine, and astatine, occupying group VIIA (17) of the periodic table.

Hydrolysis

hʌɪˈdrɒlɪsɪs/

the chemical breakdown of a compound due to reaction with water.

Hydrate

ˈhʌɪdreɪt/

a compound, typically a crystalline one, in which water molecules are chemically bound to another compound or an element.

Heat

hiːt/

the quality of being hot; high temperature.

Harmonic

hɑːˈmɒnɪk/

a component frequency of an oscillation or wave.

Hertz

həːts/

the SI unit of frequency, equal to one cycle per second.

Heliocentric (adjective)

ˌhiːlɪə(ʊ)ˈsɛntrɪk/

having or representing the sun as the centre, as in the accepted astronomical model of the solar system.

Hydraulics

hʌɪˈdrɔːlɪks,-ˈdrɒlɪks/

the branch of science and technology concerned with the conveyance of liquids through pipes and channels, especially as a source of mechanical force or control.

Hexose

ˈhɛksəʊz,-s/

any of the class of simple sugars whose molecules contain six carbon atoms, such as glucose and fructose.

Isotope

ˈʌɪsətəʊp/

each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei.

Isoelectronic (adjective)

ˌʌɪsəʊɪlɛkˈtrɒnɪk,-ɛl-/

having the same numbers of electrons or the same electronic structure.

Ion

ˈʌɪən/

an atom or molecule with a net electric charge due to the loss or gain of one or more electrons.

Impulse

ˈɪmpʌls/

a force acting briefly on a body and producing a finite change of momentum.

Interference

ɪntəˈfɪər(ə)ns/

the combination of two or more electromagnetic waveforms to form a resultant wave in which the displacement is either reinforced or cancelled.

Intellectual

ˌɪntəˈlɛktʃʊəl,-tjʊəl/

a person possessing a highly developed intellect.

Insulin

ˈɪnsjʊlɪn/

a hormone produced in the pancreas by the islets of Langerhans, which regulates the amount of glucose in the blood.

Interphase

ˈɪntəfeɪz/

the resting phase between successive mitotic divisions of a cell, or between the first and second divisions of meiosis.

Intercellular

ɪntəˈsɛljʊlə/

located or occurring between cells.

Intron

ˈɪntrɒn/

a segment of a DNA or RNA molecule which does not code for proteins and interrupts the sequence of genes.

Joule

dʒuːl/

The joule, symbol J, is a derived unit of energy, work, or amount of heat in the International System of Units

Jerk

dʒəːk/

a quick, sharp, sudden movement.

Jet

dʒɛt/

a rapid stream of liquid or gas forced out of a small opening.

Java

ˈdʒɑːvə/

a general-purpose computer programming language designed to produce programs that will run on any computer system.

Just (adjective)

dʒʌst/

based on or behaving according to what is morally right and fair.

Joliotium

ˌdʒɒlɪˈəʊtɪəm/

the name proposed by IUPAC for the chemical element of atomic number 105, now called dubnium.

Jaw

dʒɔː/

each of the upper and lower bony structures in vertebrates forming the framework of the mouth and containing the teeth.

Joystick

ˈdʒɔɪstɪk/

an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling.

Joypad

an input device for a computer games console which uses buttons to control the motion of an image on the screen.

Joint

dʒɔɪnt/

a point at which parts of an artificial structure are joined.

Kinematics

ˌkɪnɪˈmatɪks,ˌkʌɪn-/

the branch of mechanics concerned with the motion of objects without reference to the forces which cause the motion.

Kinetic (adjective)

kɪˈnɛtɪk,kʌɪ-/

relating to or resulting from motion.

Ketosis

kɪˈtəʊsɪs/

a condition characterized by raised levels of ketone bodies in the body, associated with abnormal fat metabolism and diabetes mellitus.

Kilogram

ˈkɪləgram/

the SI unit of mass, equivalent to the international standard kept at Sèvres near Paris (approximately 2.205 lb).

ketone

ˈkiːtəʊn/

an organic compound containing a carbonyl group =C=O bonded to two hydrocarbon groups, made by oxidizing secondary alcohols.

Kelvin

ˈkɛlvɪn/

the SI base unit of thermodynamic temperature, equal in magnitude to the degree Celsius.

Karyotype

ˈkarɪə(ʊ)tʌɪp/

the number and visual appearance of the chromosomes in the cell nuclei of an organism or species.

Kilowatt

ˈkɪləwɒt/

a measure of one thousand watts of electrical power.

Krypton

ˈkrɪptɒn/

the chemical element of atomic number 36, a member of the noble gas series. It is obtained by distillation of liquid air, and is used in some kinds of electric light.

Kurchatovium

ˌkəːtʃəˈtəʊvɪəm/

a name proposed in the Soviet Union for the artificial radioactive element of atomic number 104, now called rutherfordium.

Liquid

ˈlɪkwɪd/

a substance that flows freely but is of constant volume, having a consistency like that of water or oil.

Lanthanide

ˈlanθənʌɪd/

any of the series of fifteen metallic elements from lanthanum to lutetium in the periodic table (atomic numbers 57–71).

Literature

ˈlɪt(ə)rətʃə/

written works, especially those considered of superior or lasting artistic merit.

Lithium

ˈlɪθɪəm/

the chemical element of atomic number 3, a soft silver-white metal. It is the lightest of the alkali metals.

Lymphocyte

a form of small leucocyte (white blood cell) with a single round nucleus, occurring especially in the lymphatic system.

Light

lʌɪt/

the natural agent that stimulates sight and makes things visible.

Lamella

ləˈmɛlə/

a thin layer, membrane, or plate of tissue, especially in bone.

Lumen

ˈluːmən/

the central cavity of a tubular or other hollow structure in an organism or cell.

Lipid

ˈlɪpɪd/

any of a class of organic compounds that are fatty acids or their derivatives and are insoluble in water but soluble in organic solvents.

Lysosome

ˈlʌɪsəsəʊm/

an organelle in the cytoplasm of eukaryotic cells containing degradative enzymes enclosed in a membrane.

Magnesium

magˈniːzɪəm/

the chemical element of atomic number 12, a silver-white metal of the alkaline earth series.

Membrane

ˈmɛmbreɪn/

a pliable sheet-like structure acting as a boundary, lining, or partition in an organism.

Motion

ˈməʊʃ(ə)n

the action or process of moving or being moved.

Momentum

məˈmɛntəm/

the quantity of motion of a moving body, measured as a product of its mass and velocity.

Mass

mas/

a large body of matter with no definite shape

Mole

məʊl/

the SI unit of amount of substance, equal to the quantity containing as many elementary units as there are atoms in 0.012 kg of carbon-12.

Matter

ˈmatə/

physical substance in general, as distinct from mind and spirit; (in physics) that which occupies space and possesses rest mass, especially as distinct from energy.

Molecule

ˈmɒlɪkjuːl/

a group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction.

Microscope

ˈmʌɪkrəskəʊp/

an optical instrument used for viewing very small objects, such as mineral samples or animal or plant cells, typically magnified several hundred times.

Modelling

ˈmɒd(ə)lɪŋ/

the activity of making three-dimensional models.

Node

nəʊd/

the part of a plant stem from which one or more leaves emerge, often forming a slight swelling.

Neutron

ˈnjuːtrɒn/

a subatomic particle of about the same mass as a proton but without an electric charge, present in all atomic nuclei except those of ordinary hydrogen.

Nucleon

ˈnjuːklɪɒn/

a proton or neutron.

Nucleus

ˈnjuːklɪəs/

the central and most important part of an object, movement, or group, forming the basis for its activity and growth.

Nucleotide

ˈnjuːklɪətʌɪd/

a compound consisting of a nucleoside linked to a phosphate group. Nucleotides form the basic structural unit of nucleic acids such as DNA.

Nitrogen

ˈnʌɪtrədʒ(ə)n/

the chemical element of atomic number 7, a colourless, odourless unreactive gas that forms about 78 per cent of the earth's atmosphere.

Neon

ˈniːɒn/

the chemical element of atomic number 10, an inert gaseous element of the noble gas group.

Ninhydrin

nɪnˈhʌɪdrɪn/

a synthetic crystalline compound which forms deeply coloured products with primary amines and is used in analytical tests for amino acids.

Nitrate

a salt or ester of nitric acid, containing the anion NO3− or the group —NO3

Nitrite

ˈnʌɪtrʌɪt/

a salt or ester of nitrous acid, containing the anion NO2− or the group —NO2.

Optics

ˈɒptɪks/

the scientific study of sight and the behaviour of light, or the properties of transmission and deflection of other forms of radiation.

Orbit

ˈɔːbɪt/

the regularly repeated elliptical course of a celestial object or spacecraft about a star or planet.

Organism

ˈɔːg(ə)nɪz(ə)m/

an individual animal, plant, or single-celled life form.

Origin

ˈɒrɪdʒɪn/

a fixed point from which coordinates are measured

Oscillation

ˌɒsɪˈleɪʃn/

movement back and forth in a regular rhythm.

Osmosis

ɒzˈməʊsɪs/

a process by which molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one.

Oxidant

ˈɒksɪd(ə)nt/

an oxidizing agent.

Oxidation

ɒksɪˈdeɪʃ(ə)n/

the process or result of oxidizing or being oxidized.

Oxygen

ˈɒksɪdʒ(ə)n/

a colourless, odourless reactive gas, the chemical element of atomic number 8 and the life-supporting component of the air.

Ozone

ˈəʊzəʊn/

a colourless unstable toxic gas with a pungent odour and powerful oxidizing properties, formed from oxygen by electrical discharges or ultraviolet light.

Parallax

ˈparəlaks/

the effect whereby the position or direction of an object appears to differ when viewed from different positions, e.g. through the viewfinder and the lens of a camera.

Permeability

pəːmɪəˈbɪlɪti/

a quantity measuring the influence of a substance on the magnetic flux in the region it occupies.

Permittivity

ˌpəːmɪˈtɪvɪti/

the ability of a substance to store electrical energy in an electric field.

Phospholipid

ˌfɒsfə(ʊ)ˈlɪpɪd/

a lipid containing a phosphate group in its molecule, e.g. phosphatidylcholine.

Pitch

pɪtʃ/

the quality of a sound governed by the rate of vibrations producing it; the degree of highness or lowness of a tone.

Plasticity

plaˈstɪsɪti/

the quality of being easily shaped or moulded.

Power

ˈpaʊə/

the ability or capacity to do something or act in a particular way.Pressure

ˈprɛʃə/

continuous physical force exerted on or against an object by something in contact with it.

Projectile (adjective)

prə(ʊ)ˈdʒɛktʌɪl,-tɪl/

propelled with great force.

Pulse

pʌls/

a single disturbance that moves through a medium from one point to the next point.

Quantum

ˈkwɒntəm/

a discrete quantity of energy proportional in magnitude to the frequency of the radiation it represents.

Quotient

ˈkwəʊʃ(ə)nt/

a result obtained by dividing one quantity by another.

Quark

kwɑːk,kwɔːk/

any of a number of subatomic particles carrying a fractional electric charge, postulated as building blocks of the hadrons.

Quadrivalent (adjective)

ˌkwɒdrɪˈveɪl(ə)nt/

having a valency of four.

Quadrupole

ˈkwɒdrʊpəʊl/

a distribution of electric charge or magnetization consisting of four equal monopoles, or two equal dipoles, arranged close together with alternating polarity and operating as a unit.

Quartz

kwɔːts/

a hard mineral consisting of silica, found widely in igneous and metamorphic rocks and typically occurring as colourless or white hexagonal prisms.

Quadrant

ˈkwɒdr(ə)nt/

each of four quarters of a circle.

Quantitative (adjective)

ˈkwɒntɪˌtətɪv,-ˌteɪtɪv/

relating to, measuring, or measured by the quantity of something rather than its quality.

Qualitative (adjective)

ˈkwɒlɪtətɪv/

relating to, measuring, or measured by the quality of something rather than its quantity.

Quench (verb)

kwɛn(t)ʃ/

rapidly cool (red-hot metal or other material), especially in cold water or oil.

Radar

ˈreɪdɑː/

an object-detection system that uses radio waves to determine the range, altitude, direction, or speed of objects.

Radian

ˈreɪdɪən/

a unit of measurement of angles equal to about 57.3°, equivalent to the angle subtended at the centre of a circle by an arc equal in length to the radius.

Radiation

reɪdɪˈeɪʃ(ə)n/

the emission of energy as electromagnetic waves or as moving subatomic particles, especially high-energy particles which cause ionization.

Radical

ˈradɪk(ə)l/

a group of atoms behaving as a unit in a number of compounds.

Radioactive (adjective)

ˌreɪdɪəʊˈaktɪv/

emitting or relating to the emission of ionizing radiation or particles.

Radium

ˈreɪdɪəm/

the chemical element of atomic number 88, a rare radioactive metal of the alkaline earth series.

Ray

reɪ/

each of the lines in which light (and heat) may seem to stream from the sun or any luminous body, or pass through a small opening.

Reductionism

rɪˈdʌkʃ(ə)nɪz(ə)m/

the practice of analysing and describing a complex phenomenon in terms of its simple or fundamental constituents, especially when this is said to provide a sufficient explanation.

Resonance

ˈrɛz(ə)nəns/

the property of having a molecular structure which cannot adequately be represented by a single structural formula but is a composite of two or more structures of higher energy.

Ribosome

ˈrʌɪbə(ʊ)səʊm/

a minute particle consisting of RNA and associated proteins found in large numbers in the cytoplasm of living cells.

Scalar (adjective)

ˈskeɪlə/

(of a quantity) having only magnitude, not direction.

Smog

smɒg/

fog or haze intensified by smoke or other atmospheric pollutants.

Sound

saʊnd/

vibrations that travel through the air or another medium and can be heard when they reach a person's or animal's ear.

Speed

spiːd/

the rate at which someone or something moves or operates or is able to move or operate.

Strain (verb)

streɪn/

the magnitude of a deformation, equal to the change in the dimension of a deformed object divided by its original dimension.

Streamline (verb)

ˈstriːmlʌɪn/

design or provide with a form that presents very little resistance to a flow of air or water, increasing speed and ease of movement.

Stress

strɛs/

pressure or tension exerted on a material object.

Silicon

ˈsɪlɪk(ə)n/

the chemical element of atomic number 14, a non-metal with semiconducting properties, used in making electronic circuits.

Symmetry

ˈsɪmɪtri/

the quality of being made up of exactly similar parts facing each other or around an axis.

Syngas

ˈsɪngas/

short for synthesis gas.

Temperature

ˈtɛmp(ə)rətʃə/

the degree or intensity of heat present in a substance or object, especially as expressed according to a comparative scale and shown by a thermometer or perceived by touch.

Tension

ˈtɛnʃ(ə)n/

the state of being stretched tight.

Thermodynamics

ˌθəːmə(ʊ)dʌɪˈnamɪks/

a branch of physics concerned with heat and temperature and their relation to energy and work.

Thymine

ˈθʌɪmiːn/

a compound which is one of the four constituent bases of nucleic acids. A pyrimidine derivative, it is paired with adenine in double-stranded DNA.

Torque

tɔːk/

a force that tends to cause rotation.

Transcription

tranˈskrɪpʃ(ə)n,trɑːn-/

the process of transcribing RNA, with existing DNA serving as a template, or vice versa.

Translation

transˈleɪʃ(ə)n,trɑːns-,-nz-/

the process by which a sequence of nucleotide triplets in a messenger RNA molecule gives rise to a specific sequence of amino acids during synthesis of a polypeptide or protein.

Trigonometry

ˌtrɪgəˈnɒmɪtri/

the branch of mathematics dealing with the relations of the sides and angles of triangles and with the relevant functions of any angles.

Tritium

ˈtrɪtɪəm/

a radioactive isotope of hydrogen with a mass approximately three times that of the usual isotope.

Tune

tjuːn/

a melody, especially one which characterizes a certain piece of music.

Ultracentrifuge

ʌltrəˈsɛntrɪfjuːdʒ/

a very fast centrifuge used to precipitate large biological molecules from solution or separate them by their different rates of sedimentation.

Ultrasonic (adjective)

ʌltrəˈsɒnɪk/

of or involving sound waves with a frequency above the upper limit of human hearing.

Unicellular (adjective)

ˌjuːnɪˈsɛljʊlə/

(of protozoans, certain algae, spores, etc.) consisting of a single cell.

Unification

ˌjuːnɪfɪˈkeɪʃ(ə)n/

the process of being united or made into a whole.

Union

ˈjuːnjən,-ɪən/

the set that comprises all the elements (and no others) contained in any of two or more given sets.

Unit

ˈjuːnɪt/

a quantity chosen as a standard in terms of which other quantities may be expressed.

Univalent

ˌjuːnɪˈveɪl(ə)nt/

another term for monovalent.

Upthrust

ˈʌpθrʌst/

the upward force that a liquid or gas exerts on a body floating in it.

Uracil

ˈjʊərəsɪl/

a compound found in living tissue as a constituent base of RNA. In DNA it is replaced by thymine.

Uranium

jʊˈreɪnɪəm/

the chemical element of atomic number 92, a dense grey radioactive metal used as a fuel in nuclear reactors.

Vacuum

ˈvakjʊəm/

a space entirely devoid of matter.

Valence

ˈveɪl(ə)ns/

relating to or denoting electrons involved in or available for chemical bond formation.

Vanadium

vəˈneɪdɪəm/

the chemical element of atomic number 23, a hard grey metal of the transition series, used to make alloy steels.

Vane

veɪn/

a broad blade attached to a rotating axis or wheel which pushes or is pushed by wind or water.

Vector

ˈvɛktə/

a quantity having direction as well as magnitude, especially as determining the position of one point in space relative to another.

Velocity

vɪˈlɒsɪti/

the speed of something in a given direction.

Vibration

vʌɪˈbreɪʃ(ə)n/

an instance of vibrating.

Viscosity

vɪˈskɒsɪti/

the state of being thick, sticky, and semi-fluid in consistency, due to internal friction.

Voltage

ˈvəʊltɪdʒ,ˈvɒltɪdʒ/

an electromotive force or potential difference expressed in volts.

Volume

ˈvɒljuːm/

the amount of space that a substance or object occupies, or that is enclosed within a container.

Water

ˈwɔːtə/

a colourless, transparent, odourless, liquid which forms the seas, lakes, rivers, and rain and is the basis of the fluids of living organisms.

Watt

wɒt/

the SI unit of power, equivalent to one joule per second, corresponding to the rate of consumption of energy in an electric circuit where the potential difference is one volt and the current one ampere.

Watt-hour

wɒt-ˈaʊə/

a measure of electrical energy equivalent to a power consumption of one watt for one hour.

Wattmeter

ˈwɒtmiːtə/

a meter for measuring electric power in watts.

Wave

weɪv/

a periodic disturbance of the particles of a substance which may be propagated without net movement of the particles

Waveform

ˈweɪvfɔːm/

a curve showing the shape of a wave at a given time.

Wavelengthˈweɪvlɛŋθ,-lɛŋkθ/

the distance between successive crests of a wave, especially points in a sound wave or electromagnetic wave.

Weight

weɪt/

a body's relative mass or the quantity of matter contained by it, giving rise to a downward force; the heaviness of a person or thing.

Whey

weɪ/

the watery part of milk that remains after the formation of curds.

Work

wəːk/

the exertion of force overcoming resistance or producing molecular change.

X

ɛks/

the first unknown quantity in an algebraic expression, usually the independent variable.

Xanthate

ˈzanθeɪt/

a salt or ester of xanthic acid.

Xanthine

ˈzanθiːn/

a crystalline compound found in blood and urine which is an intermediate in the metabolic breakdown of nucleic acids to uric acid.

Xanthophyll

ˈzanθə(ʊ)fɪl/

a yellow or brown carotenoid plant pigment which causes the autumn colours of leaves.

x-axis

ɛks-ˈaksɪs/

the principal or horizontal axis of a system of coordinates, points along which have a value of zero for all other coordinates.

Xenobiotic (adjective)

ˌzɛnə(ʊ)bʌɪˈɒtɪk/

relating to or denoting a substance, typically a synthetic chemical, that is foreign to the body or to an ecological system.

Xenogamy

zɛˈnɒgəmi/

fertilization of a flower by pollen from a flower on a genetically different plant.

Xenon

ˈzɛnɒn,ˈziː-/

the chemical element of atomic number 54, a member of the noble gas series. It is obtained by distillation of liquid air, and is used in some specialized electric lamps.

X-ray

ˈɛksreɪ/

an electromagnetic wave of high energy and very short wavelength, which is able to pass through many materials opaque to light.

Xylem

ˈzʌɪləm/

the vascular tissue in plants which conducts water and dissolved nutrients upwards from the root and also helps to form the woody element in the stem.

Yard

jɑːd/

a unit of linear measure equal to 3 feet (0.9144 metre).

y-axis

ˈwaɪ-ˈaksɪs/

the secondary or vertical axis of a system of coordinates, points along which have a value of zero for all other coordinates.

Year

jɪə,jəː/

the time taken by the earth to make one revolution around the sun.

yeast

jiːst/

a microscopic fungus consisting of single oval cells that reproduce by budding, and capable of converting sugar into alcohol and carbon dioxide.

yocto- (combining form)

ˈjɒktəʊ/

(used in units of measurement) denoting a factor of 10−24.

Yolk

jəʊk/

the yellow internal part of a bird's egg, which is surrounded by the white, is rich in protein and fat, and nourishes the developing embryo.

yotta- (combining form)

ˈjɒtə/

(used in units of measurement) denoting a factor of 1024.

Ytterbium

ɪˈtəːbɪəm/

the chemical element of atomic number 70, a silvery-white metal of the lanthanide series.

Yttrium

ˈɪtrɪəm/

the chemical element of atomic number 39, a greyish-white metal generally included among the rare earth elements.

Zeolite

ˈziːəlʌɪt/

any of a large group of minerals consisting of hydrated aluminosilicates of sodium, potassium, calcium, and barium.

Zepto- (combining form)

ˈzɛptəʊ/

(used in units of measurement) denoting a factor of 10−21

Zero (noun)

ˈzɪərəʊ/

no quantity or number; nought; the figure 0.

zetta- (combining form)

ˈzɛtə/

(used in units of measurement) denoting a factor of 1021.

Zinc

zɪŋk/

the chemical element of atomic number 30, a silvery-white metal which is a constituent of brass and is used for coating (galvanizing) iron and steel to protect against corrosion.

Zincateˈzɪŋkeɪt/

. a salt of zinc hydroxide, such as Zn(OH)2.

Zincite

ˈzɪŋkʌɪt/

a rare deep red or orange-yellow mineral consisting chiefly of zinc oxide, occurring typically as granular or foliated masses.

Zirconium

zəːˈkəʊnɪəm/

the chemical element of atomic number 40, a hard silver-grey metal of the transition series.

Zwitterion

ˈzwɪtərʌɪən,ˈtsvɪ-/

a molecule or ion having separate positively and negatively charged groups.

Zygote

ˈzʌɪgəʊt/

a diploid cell resulting from the fusion of two haploid gametes; a fertilized ovum.