Part 1: Engage (Anchoring Phenomenon)

Phenomenon: Sprinters running a 100-meter dash often feel a burning sensation in their muscles and breathe heavily after the race. In contrast, marathon runners pace themselves for hours without experiencing that rapid, intense “burn” until they hit “the wall.”

Questions:

  1. What do you think causes the “burn” in a sprinter’s muscles?
  2. Why do you think sprinters breathe so heavily after the race is over?
  3. What is the fundamental difference in how these athletes’ bodies are getting energy?

Part 2: Explore (Simulation Investigation)

Access the simulation: Cycling of Matter & Energy Flow: Aerobic vs. Anaerobic Conditions

Investigation Instructions:

  1. Keep the Oxygen Availability at 100%. This represents an environment where the cell has plenty of oxygen (like pacing during a marathon).
    • Observe the “Matter Outputs”. What molecules are produced?
    • Record the total ATP yield displayed.
    • Note the “Efficiency” status.
  2. Slowly decrease the Oxygen Availability to 0%. This represents an environment where the cell’s oxygen supply is depleted (like an all-out sprint).
    • What new molecule appears in the “Matter Outputs”?
    • How does the total ATP yield change?
    • What happens to the “Efficiency” status?
  3. Move the slider to a mixed state (e.g., 50% oxygen). How does the cell adapt its energy production when oxygen is limited but not completely gone?

Part 3: Explain (Sensemaking)

Using your data and observations from the simulation, answer the following questions:

  1. Matter Cycling: How does the absence of oxygen change the way glucose (matter) is broken down? Specifically, contrast the final matter outputs of aerobic respiration with those of anaerobic respiration.
  2. Energy Flow: Explain the vast difference in ATP yield between 100% oxygen and 0% oxygen. Why is aerobic respiration considered more “efficient” for complex organisms?
  3. Connecting to the Phenomenon: Based on the simulation outputs, what specific molecule is responsible for the “burn” the sprinter feels? Why did their body have to resort to making it?

Part 4: Elaborate/Evaluate (Argumentation & Modeling)

Prompt: Construct a scientific explanation, based on evidence from the simulation, for why human muscles must shift from aerobic to anaerobic respiration during a short, intense sprint, and describe the consequences of this shift on both matter cycling and energy flow.

Your explanation must include: