Teacher resources and professional development across the curriculum

Teacher professional development and classroom resources across the curriculum

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Workshop 5

5. Photosynthesis
elodea under microscope
Photosynthesis--the process by which green plants and some microorganisms make food--is far more complex than can be presented in the video program. The raw materials for photosynthesis are carbon dioxide (CO2) and water (H2O). The energy source for photosynthesis is light.

During photosynthesis, light energy is converted into chemical energy. This energy is stored in the simple sugar glucose (CH2O), which is a carbohydrate. This carbohydrate and oxygen (O2) are the products of photosynthesis.

The simple equation for photosynthesis is:
CO2 + H2O + Energy (Light) -> (CH2O) + O2

Photosynthesis Facts:
  • The process of photosynthesis takes place in two stages. The first stage, composed of the "light" reactions, requires the presence of light (as the name implies). The products of the light reactions require further processing, which occurs during the "dark" reactions. Despite this name, the dark reactions can and do occur in the presence of light. They do not, however, require light, only the products of the light reactions.
  • Plants also respire. This means that they use some of the free oxygen that they and other photosynthesizers produce to release energy for growth, reproduction, and other life processes. Most of the oxygen produced by photosynthesis, however, is released into the environment.

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