Name_____________________________________________________date__________block__________ Cellular Respiration Lab Background: There are two important ways a cell can harvest energy from food: fermentation and cellular respiration. An analogy can be drawn between the process of cellular respiration in our cells and a car. The mitochondria are the engines of our cells where sugar is burned for fuel and the exhaust is CO2 and H2O. Note that in a car that burned fuel perfectly, the only exhaust should theoretically be CO2 and H2O also. Bromothymol Blue (BTB) Bromothymol blue is an indicator, a substance that changes color as the pH of a solution changes. Bromothymol blue is yellow in acidic solutions and blue in basic solutions. It is useful to test for the presence of CO2 because when CO2 mixes with H2O, the product is an acid. CO2 + H2O H2CO3 carbon dioxide water carbonic acid Question: How is CO2 output affected by exercise? Task: Design your own experiment to test the effect of exercise on respiration. With your group: 1. Develop a hypothesis 2. Decide what procedures you will use 3. What materials will you use? 4. What will you record? 5. Draw a conclusion Completely write the procedure BEFORE you start, then gather materials and begin. Record everything you do in great detail. Remember - science relies on evidence and evidence should be repeatable under similar conditions. NOTE! You will need to design your lab and schedule a time with Mrs. Siler to perform your lab. This can be done before or after school, our during our extra help time. It is your responsibility to complete this assignment! Question: How is CO2 output affected by exercise? Your Experiment Hypothesis: How do you and your partners think that CO2 output will be affected by exercise? Procedure: Write a step-by-step procedure for how you will perform your experiment. Variables: Independent variable: Dependent variable: Control Variables: (list more than 1) Materials: List ALL materials you will use to complete your experiment. (See below for a list of what is available to use) Are the above sections COMPLETE? If not, GO BACK! Observations: (Data) Use this space any way you like to record your data. Conclusion: What did your experiment show? Materials available for your use: Flasks Beakers Straws Bromothymol blue (BTB) timers Goggles Lab aprons (others available upon request!) USE YOUR OWN THOUGHTS, WORDS, BRAINS!!!!!!!!!!! Discussion: 1. What does your body need in order to exercise? 2. What did you observe about the amount of carbon dioxide the subject released after exercise? 3. Where is the carbon dioxide coming from? 4. What are the signs that our body is using energy faster? 5. What would happen if our body didn’t have food stored? 6. In what organelle is the process of cellular respiration taking place? 7. Do plants perform cellular respiration?