Module 5 Intro
1. Module 5 Intro
1.15. Lesson 3 intro
Module 5—Photosynthesis and Cellular Respiration
Lesson 3—The Light-Independent Reactions of Photosynthesis
Get Focused
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What if humans decide to colonize space? How could they apply information about photosynthesis to make colonization sustainable? In Lesson 2 you investigated how energy was converted during photosynthesis. You also know that plants absorb carbon dioxide and use it to make sugar.
In Lesson 3 you will study how plants are able to produce biomass.
“An estimated 170 billion tons of dry plant biomass is produced through photosynthesis by all plants on Earth each year. For every dry ton of new plant biomass produced through photosynthesis, approximately 1273 kg of oxygen are added to the atmosphere and approximately 1636 kg of carbon dioxide are removed. Studies conducted by the US and Russian space agencies show that astronauts consume approximately 0.9 kg of oxygen and exhale approximately 1.1 kg of carbon dioxide every 24 h. Based on this data, approximately 0.64 kg of new dry plant material must be produced by photosynthesis each day to supply the oxygen needs of one adult.”
Dr. B. C. Wolverton
Knowing how much plant matter is needed to produce enough oxygen to support life is valuable information. The values for oxygen production and carbon dioxide use stated in the previous quotation could be very helpful for scientists trying to design efficient crops or gardens able to sustain life in a space colony. Since the light-independent reactions of photosynthesis require carbon dioxide and produce biomass, this information is of great interest to researchers.
You may have noticed from the name of this process that light does not appear to be necessary. Does this mean that this series of reactions could happen without sunlight? As you work through this lesson, consider the necessary reactants for this step to occur and determine if they will be available to plants in space.
In this lesson the following essential questions will be examined:
- How is carbon dioxide used during the light-independent reactions of photosynthesis?
- How are ATP and NADPH produced by the light-dependent reactions used to make glucose?
Module 5: Lesson 3 Assignment
Your teacher-marked Module 5: Lesson 3 Assignment requires you to submit a response to the following:
- TR 1. You Be the Critic
- Reflect and Connect
You can access your Module 5: Lesson 3 Assignment. You can print off the assignment or save the download to your computer. Your answers can be saved on this document to your course folder.
You must decide what to do with the questions that are not marked by the teacher.
Remember that these questions provide you with the practice and feedback that you need to successfully complete this course. You should respond to all the questions and place those answers in your course folder.