In addition to releasing oxygen to the atmosphere, plants are used for making medicines, perfumes, lotions, clothes, paper, and buildings. People also use plants as a source of amino acids and food energy.

By understanding photosynthesis, technologies that could help alleviate food or fuel shortages can be explored.

Plants do require sunlight to perform one part of photosynthesis. This part that requires sunlight is called the light-dependent reactions of plants. It is our topic of discussion in this lesson.

In this lesson, you will explore the following essential questions:

• How does the energy from light flow through living systems?
• How does oxygen become a product of photosynthesis?