A tree is a factory

A tree is like a self-generating biochemical plant that uses energy from the sun to convert carbon dioxide and water into glucose and oxygen. This process, called photosynthesis, is the most important process on Earth to maintain life. Trees are made up of different types of cells. Photosynthesis takes place in organelles called chloroplasts.

The chemical equation for photosynthesis is: 6H₂O (water) + 6CO₂ (carbon dioxide) + sunlight → C₆H₁₂O₆ (glucose) + 6O₂ (oxygen).

Can you photosynthesize? Move the water and carbon dioxide to the right place and see what happens! The cell model gives you a closer look at the structure of wood.

The cell structure of a tree

The photosynthetic tissues in leaves and needles and the seed storage tissues are living tissues where the important vital functions take place. Water and nutrients are transported by lignified, dead conductive tissue; in conifers these are called tracheids and in deciduous trees, vessel elements. Covering tissues protect the leaves, stem and roots and conduct carbon dioxide, oxygen and water to the tissues inside the tree. The parenchyma cells of the resin canals of coniferous trees, for example, are secretory tissues. The lengthening of the tree takes place in the shoot and root apical meristems, and the growth in thickness takes place in the cambium layer. Cellulose is the structural component of wood cell wall. Lignin fills the spaces in the cell wall, glues the fibres together and causes the wall to become woody. Alongside lignin, hemicellulose is another filler found in the cell wall, which strengthens the wall structure. In addition, wood contains various extracts. The cells of deciduous and coniferous trees are different in their form and order, for instance. That is why various tree species are different, also in their characteristics.