Describe the differences between aerobic respiration and anaerobic respiration in humans.

Pearson Edexcel International GCSE Biology (4BI1) — 2.7 Respiration · Describe · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Model answer (4 marks)

Aerobic respiration requires oxygen, whereas anaerobic respiration does not.
Aerobic respiration produces carbon dioxide and water; anaerobic respiration produces lactic acid in animals.
Aerobic respiration releases more energy (≈30 kJ mol⁻¹) than anaerobic respiration (≈2 kJ mol⁻¹).
Aerobic respiration takes place in the mitochondria, while anaerobic respiration occurs in the cytoplasm.

Examiner tips

Use the exact terms ‘aerobic’ and ‘anaerobic’ and mention oxygen requirement first.
Show the products (CO₂ & H₂O vs lactic acid) and the organelles (mitochondria vs cytoplasm).
Include the energy difference to hit the full 4 marks.

Common mistakes

Confusing the location of glycolysis with the whole aerobic pathway.
Saying anaerobic produces ‘ethanol’ instead of lactic acid for humans.
Omitting the energy comparison or giving an incorrect value.

Mark scheme (4 marks)

Aerobic respiration requires oxygen / anaerobic respiration does not require oxygen
Aerobic respiration produces carbon dioxide and water; anaerobic respiration produces lactic acid (in animals/humans)
Aerobic respiration releases more energy than anaerobic respiration
Aerobic respiration takes place in the mitochondria; anaerobic respiration takes place in the cytoplasm

Key terms in this question

aerobic respiration · anaerobic respiration