Photosynthesis uses light energy to make food.

subheader icon Explore photosynthesis in action.

OBJECTIVE: To examine how ATP, NADPH, and oxygen are produced during the light reactions for use in the Calvin cycle

View the animation below, and then scroll down to answer the questions at the bottom of the page.

Answer the following questions in the boxes provided. When you have completed a question, click the Check Your Answer button for feedback.

1. Describe how the light reactions and the Calvin cycle are dependent upon one another.

2. Why is oxygen considered a waste product of photosynthesis?

3. If the Calvin cycle can produce sugar without the presence of sunlight, why is the sun essential to photosynthesis?

You now have all the information you need to take back to the laboratory. And you're not alone. A number of scientists around the world have been working on this problem: designing photoelectrochemical cells, making molecules that mimic chlorophyll, and even developing tiny computer chips to act as electron transport chains. Think about which facet of sugar production you would recommend that the bioengineer investigate.

When you have completed the questions, go on to the next activity.

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