Key terms & definitions

A biological catalyst, usually a protein, that speeds up a chemical reaction without being used up.

The ability of an enzyme to catalyse only a particular reaction because only a substrate with a complementary shape can bind to its active site.

The ability of an enzyme to bind a particular substrate because their shapes are complementary.

A temporary association formed when a substrate is bound to an enzyme’s active site.

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

Brown discolouration caused by enzyme-controlled reactions involving oxygen in cut or damaged fruit and vegetables.

An exclusive OR gate, also called XOR. With two inputs, its output is HIGH only when the inputs are different.

The celebrations held on the day after an Athenian wedding, including the presentation of wedding gifts.

One of five annually serving Spartan officials who exercised oversight of government and had responsibilities for military mobilisation.

A long narrative poem about important deeds and events, often involving heroes, warfare and gods.

The point on Earth’s surface directly above an earthquake’s focus.

A long poem recounting the adventures and achievements of a hero.

A long narrative poem, often concerned with a people’s heroes, history or legends.

A long poem about heroic characters and their deeds.

An extended comparison, often using ‘like’ or ‘as’, which connects an epic event or character with another scene to develop its meaning and impact.

An ancient philosophy associated with Epicurus that sought freedom from fear and disturbance, including fear of divine intervention. Cassius's former allegiance helps explain his previous rejection of omens.

An outbreak of disease affecting many people in a community or region over a particular period.

The study of patterns of disease in populations, including how diseases spread and how they can be controlled.

The study of the occurrence, distribution and possible causes of health conditions in populations.

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

The outer tissue covering a plant organ, providing protection.

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

The outer layer of the skin, which forms a protective barrier and contains temperature receptors.

The 30,000 young Persians trained and armed in the Macedonian manner whose incorporation into Alexander’s forces helped provoke Macedonian fears of replacement.

A quotation placed before a literary work that helps frame its ideas.

Evidence provided by inscriptions: words cut or written onto surviving objects or surfaces.

The study of inscriptions: writing engraved or otherwise marked on materials such as stone or metal.

An Athenian daughter without legitimate brothers who transmitted her father's estate through the family line, rather than inheriting it with the independent control available to a male heir.

A concluding section that explains what happens to characters after the main action has been resolved.

The Titan who accepted Pandora despite Prometheus’ warning. His name means ‘hindsight’.