Respiration Equations

IGCSE Edexcel Biology
2.34-2.38 Respiration
Key Concept: Respiration releases energy (ATP) from glucose, with different products in aerobic and anaerobic conditions.

Section A: Aerobic Respiration

1. Define respiration. [2]
2. Write the word equation for aerobic respiration. [2]
3. Write the balanced symbol equation for aerobic respiration. [3]

Section B: Anaerobic Respiration

4. Write the word equation for anaerobic respiration in animals. [2]
5. Write the word equation for anaerobic respiration in plants/yeast. [2]
6. Compare the energy yield of aerobic and anaerobic respiration. [2]
Total marks: 13

Mark Scheme

1. Chemical process that releases energy from glucose in cells [2]
2. Glucose + oxygen -> carbon dioxide + water [2]
3. $C_6H_{12}O_6 + 6O_2 \to 6CO_2 + 6H_2O$ [3]
4. Glucose -> lactic acid [2]
5. Glucose -> ethanol + carbon dioxide [2]
6. Aerobic releases much more energy; anaerobic releases a small amount [2]