O LevelChemistryCambridge (CIE)Revision Notes10. Chemistry of the Environment10.3 Air Quality & ClimatePhotosynthesis

Photosynthesis (Cambridge (CIE) O Level Chemistry): Revision Note

Exam code: 5070

Written by: Stewart Hird

Reviewed by: Caroline Carroll

Updated on 15 October 2026

Photosynthesis

Photosynthesis is an endothermic reaction in which energy is transferred from the environment to the chloroplasts in green plants to make glucose
The reactants for this reaction are carbon dioxide and water
Glucose and oxygen are produced
Chlorophyll (found in chloroplasts) and energy from light are required for this reaction to occur
The word equation for photosynthesis is:

Carbon dioxide + water $\to_{chlorophyll}^{light}$ glucose + oxygen

Symbol Equation for Photosynthesis

The balanced symbol equation for photosynthesis is:

6CO₂ + 6H₂O $\to_{chlorophyll}^{light}$ C₆H₁₂O₆ + 6O₂

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Reviewer: Caroline Carroll

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Caroline graduated from the University of Nottingham with a degree in Chemistry and Molecular Physics. She spent several years working as an Industrial Chemist in the automotive industry before retraining to teach. Caroline has over 12 years of experience teaching GCSE and A-level chemistry and physics. She is passionate about delivering high-quality resources to help students achieve their full potential.