C1.1 Enzymes and metabolism
Enzymes and metabolism explain how catalysts, active sites, reaction conditions and pathway regulation control cellular chemical reactions in living systems.
- Syllabus
- First assessment 2025
- Topic
- C1.1
- Level
- —
What you’ll learn
17 learning objectivesChoose one objective for a focused lesson, or study the complete topic.
Exam analysis
An aggregate view of how the complete C1.1 Enzymes and metabolism appears across past papers.
Chance of appearing56%of analysed past papers
Latest appearanceNovember 2025
Most common paperPaper1
Most tested objectives
- C1.1.8—Effects on enzyme activity66 questions
- C1.1.9—Measuring enzyme reactions36 questions
- C1.1.15 (HL)—Competitive inhibition19 questions
Common question formats
- Calculation
- Data analysis
- Definition or recall
- Diagram interpretation
- Experimental design
- Extended response
- Graph interpretation
- Structured response
Exam question appearances
November 2025Paper2 ["HL"] · TZ39(b)[ 7 ]C1.1.8—Effects on enzyme activity
November 2025Paper2 ["HL"] · TZ18(a)[ 4 ]C1.1.15 (HL)—Competitive inhibition
November 2025Paper1A ["HL"] · TZ36[ 1 ]C1.1.8—Effects on enzyme activity
November 2025Paper1A ["HL"] · TZ15[ 1 ]C1.1.8—Effects on enzyme activity
November 2025Paper1A ["SL"] · TZ14[ 1 ]C1.1.3—Anabolic and catabolic reactions
Practice this topic
14 original exam-style questions based on the patterns above.
Coverage 2010–2025 · Updated 15 Jul 2026