C1.2 Cell respiration

Cell respiration transfers energy from organic compounds into ATP through glycolysis, anaerobic pathways and aerobic mitochondrial stages, supporting usable cellular work and measurable biological activity.

What you’ll learn

17 learning objectives

Choose one objective for a focused lesson, or study the complete topic.

Exam analysis

An aggregate view of how the complete C1.2 Cell respiration appears across past papers.

Chance of appearing44%of analysed past papers

Latest appearanceNovember 2025

Most common paperPaper1

Most tested objectives

C1.2.4—Cell respiration system32 questions
C1.2.5—Anaerobic vs. aerobic respiration in humans25 questions
C1.2.6—Variables affecting rate25 questions

Common question formats

Calculation
Comparison
Data analysis
Diagram interpretation
Evaluation
Extended response
Graph interpretation
Structured response

Exam question appearances

November 2025Paper2 ["HL"] · TZ38(b)[ 5 ]C1.2.2—Life processes using ATP

November 2025Paper1A ["HL"] · TZ38[ 1 ]C1.2.6—Variables affecting rate

November 2025Paper1A ["HL"] · TZ17[ 1 ]C1.2.12 (HL)—Krebs cycle

November 2025Paper1A ["HL"] · TZ16[ 1 ]C1.2.6—Variables affecting rate

November 2025Paper1A ["HL"] · TZ35[ 1 ]C1.2.9 (HL)—Pyruvate → lactate

Practice this topic

6 original exam-style questions based on the patterns above.

Coverage 2010–2025 · Updated 15 Jul 2026