Now that you know about the structure of plant cells, in this activity, you will consider how plants use and transform energy.

In earlier lessons, you learned that the sun is a source of energy and you also learned that the sun's energy is stored in the plants and animals that fossil fuels come from. Now, you will learn more about the process that plants undergo to store energy from the sun: photosynthesis.

When light from the sun reaches the earth, some of the light is absorbed by the cells of green plants. These cells have special parts that can absorb this solar energy, and convert it to energy that the plant can use. These cell parts are called chloroplasts. Chloroplasts contain chlorophyll, which is a green-coloured chemical that assists in converting carbon dioxide and water into glucose and oxygen. Glucose is a simple carbohydrate that is rich in chemical energy which plants and animals can use. This process is referred to as photosynthesis.

You might recognize this chemical reaction from your study of chemical equations in an earlier theme:

Plants use the energy in the glucose to grow. Plants can also store energy that is not used right away in their leaves, stems, and roots for later use such as on days with little sunlight.

In the next activity, you will learn about cellular respiration, a process that is closely related to photosynthesis.