How a Leaf Works

The parts of a tree that are used to identify the species such as the leaves, bark and flowers all have different functions. They help the tree to feed, breathe, grow and reproduce.

The leaves of different trees vary in shape, size and texture, but they all contain a green substance called chlorophyll, which gives them their colour. Chlorophyll is essential for the process called photosynthesis, which takes place in the leaves. During photosynthesis, the chlorophyll absorbs light energy from the rays of the sun. The energy is used to drive a chemical reaction in which carbon dioxide, absorbed by the leaves from the atmosphere, and water is drawn up from the soil and converted into sugar and glucose. Glucose is used as food by the tree. Oxygen is also produced during this reaction and given off from the leaves. There are tiny pores distributed over the leaves' surface by which the gases enter and leave.

CARBON DIOXIDE + WATER + CHLOROPHYLL + SUNLIGHT = GLUCOSE + OXYGEN