Biology, The Science of Life

Cellular Respiration: Harvesting Chemical Energy
Part 2

cellular_respiration.ppsx
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Overview: Today’s lesson will be focused on continuing to understand how respiration breaks down the fuel energy from our foods, generating ATP (energy source). The instructor will lecture for the majority of the duration of the class (i.e. 40 minutes). This topic is difficult to grasp, therefore the instructor will progress slowly through the material and put great emphasis on the diagrams in the Power Point presentation. Afterwards, the instructor will explain the Prezi Presentation the students are required to do as a project.

Materials: The teacher will need access to the class computer, screen, and projector to present the Power Point presentation. The Power Point presentation is the media object used as a teaching tool and is available for download above. Students will need pencil and paper or their laptops to take down notes. The Power Point will be made available to the students therefore students must focus on taking notes regarding what is not presented on the slides.

Assessment: Students are required to recreate the cellular respiration pathway covered in lessons 07 and 08 onto a Prezi presentation. The project touches on the production aspect of media education. Since the process by which our bodies decompose food to obtain energy is a pathway, a great method of knowing the pathway, understanding it, and feeling comfortable with it is by recreating it. Once the project is complete, it will be an interactive tool to help study for the exam. Assignment rubric is presented at the end.

LECTURE MATERIAL:
Outline:
  • The Pathway of Electron Transport (20 minutes)
  • Chemiosmosis: The Energy Coupling Mechanism (10 minutes)
  • Review of whole pathway (10 minutes)
  • Explain the Prezi Presentation project (10 minutes) 

Open the Power Point presentation and follow it very closely. Use the white board to further emphasize the electron transport pathway and how the ATP synthase works: draw the 4 complexes and show the movement of the protons across each complex.

Electron Transport Chain
In the third stage of respiration, the electron transport chain accepts electrons from the breakdown products of the first two stages (lesson 07) and passes the electrons from one molecule to another. At the end of the chain, the electrons are combined with molecular oxygen and hydrogen ions, forming water. The energy released is used to make ATP. This mode of ATP synthesis is called oxidative phosphorylation because it is powered by the redox reactions of the electron transport chain.

Chemiosmosis
Populating the inner membrane of the mitochondrion are many copies of a protein complex called ATP synthase, the enzyme that actually makes ATP from ADP and inorganic phosphate. ATP synthase uses the energy of an existing ion gradient to power ATP synthesis. The power source for the ATP synthase is a difference in the concentration of H+ on the opposite sides of the mitochondrial membrane. This process, in which energy stored in the form of an ion gradient across a membraneis used to drive cellular work such as the synthesis of ATP, is called chemiosmosis. 


Once the material on the Power Point presentation has been covered, briefly review the whole pathway using the summary slide in the Power Point (first slide after Title slide).

After the review, explain the assignment.

Assignment Rubric:
The purpose of this assignment is to help you get familiar with the gycloysis, TCA, and ETC pathways by recreating them by doing a Prezi Presentation. You have the liberty of creativity, for example, you can draw each molecule using Paint and then uploading that image onto Prezi, or you may take an image from the internet. You man also simply recreate the way it is presented in the power point slides. This assignment is worth 20 % of your final grade and is due next class. This is an individual assignment. Send your links to Francesca.Fuoco@mail.mcgill.ca

  • Detailed pathways: includes molecule structure, name of compounds, where NAD(H), ATP, ADP, Pi, CO2, FAD(H2) are used. 10 marks
  • Pathway is in the proper order. 5 marks
  • Creativity. 5 marks

Explain how to use Prezi & Paint (on Microsoft Windows 7)

  • Watch the online tutorial as a class
  • Go to http://www.prezi.com
  • Demonstrate how to create an account
  • Give a visual demonstration of how Prezi works
  • Explain how to use paint: select the “pencil” or “paint brush” option and draw a molecule and how to save it
  • Demonstrate how to upload an image onto Prezi