Combined Science key terms

The giving out of radiation by an object, transferring energy away from it.

A formula showing the simplest whole-number ratio of the elements in a compound.

The breakdown of large fat droplets into smaller droplets, increasing the total surface area available to lipase.

A mixture in which tiny droplets of one liquid are dispersed through another. A cloudy emulsion is a positive result in the ethanol test for lipids.

A species at risk of extinction.

An organ that produces and secretes hormones directly into the bloodstream.

The system of glands that releases hormones into the bloodstream to coordinate and control processes in the body.

A change or reaction in which heat energy is taken in from the surroundings.

A reaction that takes in energy from the surroundings.

The point in a titration at which the indicator shows its lasting colour change.

A quantity that can be stored and transferred, including by doing work. Energy is a scalar measured in joules (J).

The spreading of energy into less useful stores, usually the thermal stores of the surroundings.

One of the particular energies an electron can have in an atom. Higher energy levels are further from the nucleus.

The combination of different energy resources used by a country or by the world.

A source from which energy can be obtained for uses such as transport, electricity generation or heating.

A way in which energy is held by an object or a system, such as a kinetic, chemical or thermal store.

A way in which energy is transferred between stores: mechanically, electrically, by heating or by radiation.

Additional warming caused by increased concentrations of greenhouse gases in the atmosphere.

A gradual change in an environmental factor across an area, such as increasing light intensity from shade to open ground.

Differences between individuals caused by the conditions in which they develop or live.

A biological catalyst that speeds up reactions in living systems without being used up overall.

The ability of an enzyme to act on particular substrates because their shapes are complementary to its active site.

The temporary association formed when a substrate binds to an enzyme's active site.

The study of patterns of disease in populations and the factors associated with those patterns.

The tissue covering a plant's surfaces, providing protection. In leaves, it allows light through and helps reduce water loss.

A state in which the forces balance, so the resultant force is zero.

The relative amounts of reactants and products in a mixture at equilibrium.