IGCSE Biology glossary
Catalyst
Biology editorial review is supported by the named review panel. Reviewer participation may vary by guide. Checked against Cambridge IGCSE Biology 0610 (2026–2028); last reviewed August 2026.
Definition
A substance that increases the rate of a chemical reaction without being used up or permanently changed in the process. In biological systems, enzymes act as biological catalysts.
What to include in an exam answer
When defining enzyme, always include 'biological catalyst' and 'protein'. Saying 'speeds up reactions without being used up' earns the catalyst mark.
Example in context
Define the term catalyst (2 marks): A substance that speeds up a chemical reaction without being used up or changed at the end of the reaction.
Related syllabus topic
Enzymes