Metabolite: Small (usually less than 1500 molecular weight) biological compounds involved in biochemical processes and pathways.

• Examples include cholesterol, glucose and amino acids

Metabolome: A collection of all metabolites observed in a biological system under a given set of conditions.

Metabolomics: the analysis, quantification, and interpretation of metabolite levels in biological samples with the view to characterising a metabolome. Can be carried out using a number of different approaches:

• Targeted
• Profiling
• Fingerprinting
• Global

Metabonomics: The study of changes in metabolite levels in response to drugs, diseases or toxicity, usually used when determining such changes using NMR.

Targeted Analysis: Experiments designed to look at specific metabolites of interest.

Metabolic or Metabolite Profiling: Analysis of a group of metabolites that are part of a particular group or class (e.g. sugars, lipids) or linked to a specific pathway.

Metabolic Fingerprinting: Characterising samples on the basis of their origin and/or biological relevance.

Global: (As used in the HUSERMET project). A snap-shot of the whole-cell/organism/biofluid metabolome, to observe and characterise as many metabolites as possible.