1. A Lab About Cellular Respiration

2. * 1. What is breathing? Movement of the diaphragm and rib cage change air pressure in the chest cavity during inhaling and exhaling. * 2. What is respiration? The transport of oxygen from the air to cells within the tissues and carbon dioxide in the opposite direction. (Oxygen in and Carbon Dioxide out).

3. * As you work out, your rate of breathing increases. * Bromothymol Blue is an indicator for CO 2. When the two things come into contact, the solution changes from blue to green! * We want to see if there is a difference in the time it takes the BMB to change color before and after working out

4. * Bromothymol Blue is an indicator or a stain. In other words, if you are not careful it will stain your clothes! EVERYONE must wear goggles and a lab apron today!

5. * Does exercise have an effect on the amount of CO 2 exhaled during respiration?

6. Each side of the lab has the following: * Stopwatch * Drinking straw * 1 200mL beaker with 150mL of BMB in it * 2 Flasks: “Before Exercise” and “After Exercise”

7. 1. From the beaker, measure out 50ml of Bromothymol Blue into each of your two flasks. 2. Place a straw in the beaker labeled “Before Exercise”. Have one student take a deep breath and blow into the straw, creating bubbles in the solution. Do this until you run out of breath or the solution changes from blue to green. a) While this is going, your partner is timing how long it takes to turn the solution green! When you have a time, record it on your lab! 3. Go into the hall and run up and down the stairs for 1 minute (time this!). 4. Using the same straw, repeat step 2 but now blow into the flask labeled “After Exercise”. a) Have your partner record how long it takes the solution to change from blue to green! Record it on your lab.

8. * Finish the back page of the lab including the “Analysis Questions” and the graph for question 6. * For the graph – make sure you put a title, and label your X and Y Axis. This graph is worth 5 points so take your time!