Photosynthesis and Respiration

Sunlight, grass, and clouds

Just like your cell phone needs to be charged to function, living systems also need energy. The flow of energy in living systems begins with the Sun, which is the original source of energy for just about all living organisms. Even the cells in your body use chemical energy that began as light energy from the Sun. In this topic, you will explore the process that converts light energy to chemical energy. In addition, you will examine the process that uses chemical energy to power metabolic functions.

Essential Questions

  • What role does the Sun play in how all organisms get energy?
  • What is the purpose of photosynthesis?
  • What is the purpose of cellular respiration?
  • How are the processes of photosynthesis and cellular respiration considered cyclic?