General name for a very large molecule; often used interchangeably with ‘polymer’.

The Registrar General’s social classification of the population is based on occupational status. The manual social classes are made up of people whose work is manual, e.g. building or plumbing work, and are sometimes referred to as blue-collar workers.

A change in the nervous system as a consequence of learning, by which information is stored; the inferred process that connects learning to recall.

The set of dopaminergic neurons that originate in the midbrain, substantia nigra and ventral tegementum (immediately beneath the nigra), and which project axon terminals to a wide set of forebrain structures, chiefly the nucleus accumbens and striatum, the amygdala, and the frontal cortex.

A single-stranded molecule of RNA produced by the transcription of DNA. A particular mRNA molecule carries the code for the amino acid sequence of a particular protein.

A group of sequential metabolic reactions.

The rate at which energy is used by the body. It is usually expressed in kilocalories per hour.

The sum of all the chemical reactions that take place in an organism.

The term refers to when a cancerous tumour spreads out to establish satellite tumours elsewhere.

A substance that is prescribed for heroin addicts. It is believed to have a less-addictive potency than heroin, though in this regard its use is controversial.