Module 1 Intro

Module 1—Energy Flow and the Cycling of Matter

Module Summary

 

Now that you have completed Module 1, you should have a better idea that there are two methods by which energy is captured in the biosphere. They are the processes of photosynthesis and chemosynthesis, which you studied in Lesson 1. You’ll remember that photosynthesis, which captures solar energy, is the process by which approximately 98% of terrestrial producers capture energy. The other 2% of producers live in extreme environments where they have no access to solar energy, so they rely on the process of chemosynthesis. Because the majority of terrestrial producers capture solar energy, people say that it is solar energy that maintains the biosphere!

 

What about the release of energy? Do you remember the process in which this takes place? If you are thinking of cellular respiration, you are correct. As you saw in Lesson 2, any energy in the biosphere that is converted into useful chemical energy during the photosynthetic and chemosynthetic processes is also used by producers and consumers at various trophic levels. This happens through the process of cellular respiration. Cellular respiration allows organisms to convert the chemical energy into forms of energy that sustain life.

 

Do you remember the second law of thermodynamics? It states that during any energy conversion, some energy is lost as heat—a non-usable form of energy. This heat is then radiated back into the atmosphere, where it is either released into outer space or captured by greenhouse gases and re-emitted back toward Earth’s surface.

 

It is important that you realize that cellular respiration is not only a means of radiating energy back into the biosphere. This process also allows for the flow of energy through the biosphere. In Lesson 2 you studied food chains in food webs. This allowed you to understand that animals, and the food chains they form, allow for the transfer or flow of energy in the biosphere. You also learned that only 10% of the energy acquired by an organism is passed on to the next trophic level until there is not enough energy to sustain another organism. In Lesson 2 you also learned that animals assist in the recycling of matter in the biosphere.

 

In Lesson 3 there was an explanation that the water cycle plays a central role in the cycling of all matter. Nearly all matter is able to dissolve in water. (Water is often called a universal solvent.) This makes water an excellent carrier of all molecules that make up matter. You will remember that water vapour can travel long distances and, therefore, can carry molecules between ecosystems. This allows matter anywhere in the biosphere to be replenished. The other point you learned about the water cycle in Lesson 3 is that the characteristic which allows it to work with all the other cycles also makes it quite vulnerable to pollution.

 

In Lesson 4 you found out that matter must cycle through both biotic and abiotic reservoirs in order to cycle in the biosphere. You should now know that biotic reservoirs are all living and recently living matter and abiotic reservoirs are all non-living components of the biosphere. You also learned that the whole point of recycling matter is for producers to obtain molecules from which they create organic compounds. The organic compounds formed from these recycled molecules include carbohydrates, proteins, and lipids—all of which are required for the survival of all living organisms.

 

Lesson 5 focused on the relationship of biodiversity and biomagnification with energy flow and the cycling of matter in the biosphere.

 

In Module 2 you will build on the concepts you have learned and studied in Module 1.

 

Module Assessment

 

You will be graded according to the work you completed for the lesson assignments and the module project. The module project will be the final assignment for Module 1.

 

Module Project

 

As you have worked through Module 1, you have often been asked to “look in your backyard” to give you context or something you can relate to for your learning. You may not have a traditional backyard, but you should have access to the outdoors. This is your mission for your final project. Go outdoors. If you have access to a digital camera, take a photo of something that is living outside (e.g., a blade of grass, a branch, an insect, your pet, or your foot). You can be as creative as you want and you might even get more than one living thing in your photo. If you don’t have a digital camera, make a sketch or a painting. If you are really stuck, scan a cool picture that you already have, or find an image from a magazine. Now that you have this image, present the following information:

• Map the flow of energy to the subject or subjects of your image, and demonstrate how the energy flows from the subjects in your photo. (3 marks)
  
  

• Indicate what trophic levels are occurring in your photo. (2 marks)
  
  

• Explain or show how the water cycle plays a role in your photo. (5 marks)
  
  

• Explain or show how the biogeochemical cycles play a role in your photo. (5 marks)
  
  

• Explain how biodiversity and biomagnification can be related to your photo. (5 marks)

For the format of your presentation, you may choose to write a descriptive paragraph underneath your photo, create a PowerPoint presentation, or make a poster. The choice is yours to make as long as the key points are covered.  (5 marks)

 

This module project is worth 25 marks. Have fun with it!

 

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