HBS – Lesson 12 –Recipe for Energy – Cellular Respiration
Getting Started
4 a. What is the candle made of?
Wax & Wick
4 b. In addition to the bromthymol blue, the candle, and the wooden block, what other
substance is present in the beaker?
Oxygen
4 c. What two ingredients, therefore, are involved in the burning of the candle?
Wick & Oxygen
4 d. What is released very quickly as the candle burns?
Light & Heat
4 e. If you wanted to put out the candle, what gas would need to be removed from the
candle’s environment?
Oxygen
5 a. What happened to the flame when you covered the beaker with foil? Why?
- Flame went out
- Oxygen decreases, Carbon Dioxide increases
5 b. What gas do you think remains in the covered beaker when the flame has gone out?
Carbon Dioxide
5 c. What else do you see in the beaker?
Smoke & Carbon particles
6 a. What happened to the bromthymol blue solution?
It turned a greenish- yellow color
6 b. What substance do you think caused this change?
Carbon Dioxide dissolves in the solution &
produces carbonic acid
6 c. Bromthymol blue is a special chemical called an indicator. On the basis of what you
have discovered during this inquiry, how would you define an indicator?
Bromthymol Blue is a pH indicator that changes from
blue to green to yellow depending on the concentration of carbon
dioxide dissolved in the solution.
What other indicators have you used in previous lessons in this module?
Previously we used Benedicts solution & Lugol’
solution
8. What are the two ingredients necessary for combustion of the candle and the products
that were released during the process of combustion?
Light & Heat
Words to Know from this Lesson
 Cellular Respiration - takes time to occur, occurs when glucose(nutrients) and
oxygen combine, the 3 products are energy, carbon dioxide & water.
 Oxidation – when a substance combines with oxygen. (when an apple turns brown
after biting or bike chain gets rusty when water is put on it)
 Combustion – a rapid release of energy, the products are heat & light
HBS – Lesson 12 –Recipe for Energy – Cellular Respiration
Inquiry 12.1 – Investigating Cellular Respiration
1 a. What did you see as the candle burned that would be absent in the type of oxidation
that occurs in your body cells?
Flame
1 b. What ingredient of combustion do you think is also an ingredient for cellular
respiration?
Oxygen
1 c. On the basis of what you discovered in the first section of this module, what do you
think is the second essential ingredient for cellular respiration?
Nutrients (glucose)
2 a. Starting Temperature __________ (see your pages)
2 b. Final Temperature __________
3 a. Did the temperature of the water change after you exhaled into it? If so, what was
the change?
Yes, it got warmer
3 b. What is temperature a measurement of?
Temperature is a measurement of the energy that is
released from the body in the form of heat
3 c. What would a change in the temperature of water indicate about your exhaled air?
The exhaled air is warmer than the water
3 d. How would you relate this change to a product of cellular respiration?
The change in temperature indicates that energy
released in the form of heat is a product of cellular respiration.
HBS – Lesson 12 –Recipe for Energy – Cellular Respiration
Inquiry 12.2 – Using a Model to Show Evidence of a Waste Product of Cellular
Respiration
7 a. Did you see a color change in the bromthymol blue solution in either test tube after
someone in your group had breathed into it?
Yes, greenish-yellow
7 b. In which test tube did the color change occur?
Exhaled air
7 c. What substance caused this change?
Carbon Dioxide
7 d. During what process in your cells is this substance released?
Cellular Respiration
8. What are the two products of cellular respiration that can be found in exhaled air?
Water & Carbon Dioxide
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HBS – Lesson 12 –Recipe for Energy – Cellular Respiration
Inquiry 12.3 – Exploring the Movement of Carbon Dioxide Through a Membrane
1. How do you think the carbon dioxide was carried to your lungs?
Through the bloodstream
2 d. Why do you need to rinse the outside of the membrane with water?
To prevent contamination
2 f. 1. Did the color of the bromthymol blue solution change?
Yes
If so, what caused the color change?
The color change was caused by carbon dioxide from
the carbonated water passing through the membrane
into the solution in the test tube.
2. f. 2. What does this color change tell you about the ability of carbon dioxide to pass
through membranes?
It passes through easily
2. f. 3. Through what process does carbon dioxide pass through membranes?
Diffusion
2. f. 4. How do you think oxygen passes through membranes?
Diffusion
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