Key terms & definitions

A model in which a substrate fits an enzyme’s complementary active site like a key fitting a lock.

A simplified explanation of enzyme action in which a substrate fits an enzyme's complementary active site, like a key fitting a lock.

A mystery involving a crime committed in a room that appears to have been securely closed, making entry and escape seem impossible.

An employer’s refusal to allow employees to work, used to put pressure on them during an industrial dispute.

The set of all points that satisfy a stated rule about position or distance.

A person's belief about whether outcomes are mainly controlled by their own actions (internal) or by outside forces such as luck and other people (external).

Accommodation where people paid for a bed rather than renting a permanent home; also called a ‘doss house’.

A scale on which equal steps represent multiplication by a fixed factor rather than addition of a fixed amount.

A scale in which equal steps represent multiplication by a constant factor rather than equal additions.

A scale on which equal numerical steps represent equal multiplication factors rather than equal amounts added. Each one-unit change in pH represents a tenfold change in hydrogen ion concentration.

Cutting down trees to obtain timber.

Felling trees and removing them to supply timber.

An operation that moves every bit a specified number of positions left or right, fills vacated positions with zeros and discards bits moved beyond the available positions.

An operator that works on Boolean values to produce a Boolean result, such as NOT, AND or OR.

Using the program's instructions and conditions to work out what it will do and whether its behaviour meets the requirements.

An operation that moves every bit a specified number of positions left or right, discards bits that leave the fixed-width pattern and fills vacated positions with zeros.

A diagram using standard logic gate symbols and connecting wires to show how Boolean inputs produce an output.

A diagram showing logic gates and the connections that carry signals between them.

A diagram showing how logic gates are connected to turn Boolean inputs into an output.

A mistake in an algorithm’s instructions that causes incorrect behaviour even though the instructions can be executed.

A component that applies a logical operation to one or more Boolean inputs to produce a Boolean output.

An electronic processing component that produces a digital output according to a particular rule applied to its input or inputs.

The organisation of supplies, transport and other practical needs that allow an army to operate.

The planning and management of the movement and storage of materials and goods, from suppliers through to the final customer.

An appeal to reasoning or evidence; an argument can sound logical without proving its conclusion.

The Greek term meaning ‘Word’, used of the eternal Son of God who became human in Jesus.

A world or realm of existence in Hindu cosmology.

Followers of ideas associated with John Wycliffe who emphasised the authority of the Bible and challenged aspects of Catholic teaching, clerical wealth and religious practice.

A religious movement associated with John Wycliffe and his followers that challenged the authority and power of the medieval Catholic Church.

A market where metals are traded and widely accepted reference prices for metals are established.