Tab Topics 1

Photosynthesis

The game can help...

As the students play the game, they must make sure that the robot has enough fuel to perform all of his functions. Just like a plant, the robot makes his fuel (glucose) from carbon dioxide and water, and needs to be in a sunny spot to capture light energy. Like many organisms, the robot cannot use the light energy directly; it must cause the glucose to react with oxygen to produce carbon dioxide and water, thereby releasing the chemical energy for use in the process of cellular respiration.

Photosynthesis Slideshow

Slides 4–15 describe the process of photosynthesis. They explain that it is the process that occurs in the leaves of green plants, using light energy to split water molecules, drawn through the roots, and carbon dioxide molecules, from the air, enabling the plant to produce sugar (glucose).

Download slideshow PPT

What the Textbooks Say

Most middle-school texts discuss the structure of leaves and how that relates to photosynthesis, which occurs in the leaves of green plants when they absorb light energy. The light energy splits carbon dioxide molecules from the atmosphere and water molecules drawn through the plant’s roots, enabling the plant to produce glucose; photosynthesis occurs in the presence of light. Some textbooks also explain that photosynthesis occurs in two stages: (1) the absorbed light splits water molecules to release oxygen and hydrogen atoms; (2) carbon dioxide is absorbed in the absence of light and reacts with the oxygen and hydrogen to produce glucose. Students may misunderstand the process and be left with one or more misconceptions—that plants perform only photosynthesis but not respiration, that photosynthesis occurs all the time, or that energy is produced during photosynthesis.

See supporting classroom activities