IGCSE Biology glossary
Protease
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
An enzyme that catalyses the breakdown of proteins into amino acids. Proteases include pepsin (which works in acidic conditions in the stomach) and trypsin (which works in alkaline conditions in the small intestine).
What to include in an exam answer
Use the general term 'protease' unless the question specifies pepsin or trypsin. State the product is amino acids, not 'peptides' at IGCSE level.
Example in context
State the substrate and product of protease (2 marks): Substrate: protein. Product: amino acids.
Related syllabus topic
Enzymes