Photosynthesis is the process by which plants make carbohydrates from raw materials, using energy from light. During photosynthesis:

  • light energy is absorbed by chlorophyll - a green substance found in chloroplasts in the palisade cells in the leaf
  • absorbed light energy is used to convert carbon dioxide (from the air) and water (from the soil) into a sugar called glucose
  • oxygen is released as a by-product

These equations summarise what happens in photosynthesis.

\text{carbon dioxide + water} \xrightarrow[\text{chlorophyll}]{\text{light}} \text{glucose + oxygen}

Some glucose is used for respiration, while some is converted into insoluble starch for storage. The stored starch can later be turned back into glucose and used in respiration.