Lesson 11. Anaerobic vs Aerobic Respiration
Objective: To discuss the different evidence that was gathered in order to determine how energy was made.
EQ: What evidence was gathered to prove that cellular respiration even occurs?
Bridge: Recall your activity from yesterday.
- What was the chemical formula you discovered that needed oxygen in the reactants to move forward?
- What were the two products that could come from the reactions that didn’t use oxygen?
- Which reaction did you predict would make more energy? Why?
Mini Lesson: Share out from the bridge. The predictions may vary which is great….. you may choose to do a tally for each of the reactions on who thinks what.
Using the chemical reactions from yesterday, classify the equations as either aerobic or anaerobic respiration. Have the students decide, based on observations of the formulas and the activity from yesterday, what the definition of each of these should be. (with or without oxygen)
Ethanol fermentation, where ethanol is one of its products, happens in many prokaryotic organisms like bacteria but the most well known organism is yeast.
Lactic Acid fermentation, where lactate (lactic acid) is one of its products, are used by some prokaryotic organisms (single celled organisms without a nucleus) but is most common in muscle cells of animals. For example, when you run sometimes you will get cramps. The cramps are caused by a build up of this lactic acid in your muscle cells, telling you that you need to give yourself a minute because your cells are not getting enough oxygen from your blood fast enough. Your muscles are still demanding the energy but you are not giving it the ingredients it needs to make it, so it finds another source that is not as efficient and doesn’t produce enough to meet the energy demands.
When an organism undergoes fermentation, the energy yield is 4 ATP (energy) molecules, but it takes 2 ATP molecules for the reaction to take place, so it is said that there is a net yield of 2 ATP per glucose molecule it breaks down.
When questions are asked about cellular respiration on the Regents exam, they are asking about aerobic, or oxygen-needed respiration. What was our formula for this again?
In aerobic respiration, there are several steps that the glucose molecule needs to go through before the ATP is released. The net yield is 36-38 ATP (energy) molecules per one glucose molecule and 6 O2 molecules. That is quite a bit more energy than fermentation! Most organisms, but unicellular and multicellular organisms prefer aerobic respiration: it means that the single celled organisms don’t have to constantly make energy because one glucose will give them enough energy for a little while and multicellular organisms have a means of making a lot of energy all of the time to meet the needs of all the cells in their body.
But how did scientists figure out how and where cellular respiration takes place?
Video Clips From Greatest Discoveries in Biology (these clips are on Discovery Education, but the whole video is on You Tube under Greatest Discoveries in Biology…. Might be worth DL the whole thing since all of the clips get used in some way: )
Video:
Stop after the Krebs Cycle and have kids answer:
What did Krebs do to collect evidence for the now known Krebs Cycle?
What is the reason for the cycle that they talk about? (Why would the sugar need to be broken down in all those steps?)
Mitochondia: play remainder of the clip
Describe the structure of the mitochondira.
What was Chance’s part in discovering the structure of the mitochondria?
What is the function of the mitochondria?
Give the expectations for the Work Period: You will use that information from our discussion and the videos to fill in what you have learned about cellular respiration so far as a self-created diagram and a data table, without additional resources. You will then go back to the predictions that were made in lesson 9 on what we use the oxygen for. Choose one of the predictions (does not have to be yours) and discuss why that prediction is correct or incorrect, using evidence to support your answer.
Work Period:
Create a diagram to show what happens during aerobic cellular respiration:
Organize your information in a data table about cellular respiration:
Organelle (Location) / Process Involved / Reactants / ProductsExplain how the data table and the diagram provide the same information but in just a different way of organization.
Prediction Evaluation:
Write the prediction you are evaluating here then evaluate.
Summary: Answer the EQ. Go back to your prediction about which produced more energy. Evaluate based on the information you collected today.
Closing:
Think about all of the cells in your body. Which cell or cells do you think you would find the most mitochondria in? Explain your answer.
SPED and ELL Modifications:
- Encourage students to look back in notebooks for Bridge activity
Apps and Internet Activities:
- Krebs cycle Interactive from the textbook company: (what’s great about this is that it has text that can be easily translated on iPads or netbooks using translating web2.0 tools or apps)
- Krebs cycle interactive:
- A mitochondrion quiz:
- A word document with additional reading, pictures and labeling activities:
- Aerobic and Anaerobic respiration:
Independent Practice: Reading and graphic organizer cellular respiration