35 Points
Name_____MAKEUP_________________________
Cellular Respiration Activity
Cellular Respiration is the process used by your cells to breakdown molecules, such as glucose, and
harness the energy stored in its bonds to make ATP. ATP is the energy currency of the cell. This is the
molecule that drives most of reactions that occur in your cells. The overall reaction for cellular
respiration is:
C6H12O6 + 6O2
6CO2
Reactants
+ 6H20 + ATP
Products
The reactants are the things that enter cellular respiration and the products are the things that come
out. Remember that there are many intermediate molecules that are formed in the different stages
involved in cellular respiration ( glycolysis, Krebs Cycle and the electron transport chain). These are not
listed in the overall reaction. Carbon dioxide (CO2) is a by-product of cellular respiration. CO2 is
formed in the Kreb cycle. When your cells need energy they will use cellular respiration to make this
energy available. The more energy you need, the more cellular respiration will occur. In today’s activity
we will investigate the effect exercise and gender have on the the rate from cellular respiration. We
will use bromthymol blue as an indicator. Bromothymol blue will turn from blue to yellow or green in the
presence of carbon dioxide.
Problem: How does exercise affect disposal of waste (CO2) from cellular respiration? Does
gender affect the rate of cellular respiration? Don’t answer these yet…
Pre-lab Questions
1. Hypothesis 1: I predict that exercise will increase CO2 production/decrease CO2 production
(circle one)
2. Hypothesis 2: I predict that girls/boys will have a higher rate of cellular respiration (circle one)
3. Write the 3 stages involved in cellular respiration
a. __________________________
b. __________________________
c. __________________________
Materials: Materials will be located on your tables already. Check to make sure you have all the
materials listed before beginning. If you are missing materials, notify the teacher immediately.

2 small test tubes labeled A and B (per
group)

Small plastic cup (per group)

Test tube rack (per table)

Bromothymol blue (per table)

2 straws (per group)

Stopwatch (per group)
Procedure
1. Use the given information to answer the following questions at the end of the lab.
Experimenter(s):___Mr. Jackson_________
____Mrs. Jackson____________
Subject(s):___You (as a boy)_____________
____You (as a girl)____________
Data Table 1
Data Table 1 Subject 1-Male or female?
Test Tube
A (before exercise)
Time for solution to
change color(sec)
35 sec
B (after exercise)
26 sec
Test Tube
A (before exercise)
Time for solution to
change color(sec)
32 sec
B (after exercise)
24 sec
Data Table 2
Average Time
Average Time
for Girls (sec)
for Boys (sec)
8
9
Subject 2- Male or female?
Analysis/Conclusion Questions
1. What process in your body produces carbon dioxide?
_______________________________________________________________________
_______________________________________________________________________
2. How does exercise affect this process?
_______________________________________________________________________
_______________________________________________________________________
3. What happens to the carbon dioxide you produce?
_______________________________________________________________________
_______________________________________________________________________
4. How did exercise affect the time for the solution to change color? Boys vs. girls?
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
5. Did these results support/reject your hypothesis?
_________________________________________________________________________
_________________________________________________________________________
6.
If you saw a difference between the rate of respiration in boys vs girls, propose a reason why.
If not, propose a reason why there was no difference.
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
Grading Rubric
2 pts per pre-lab question (6 total)
2 pts per data table (6 total)
3 pts per analysis/conclusion question (18 total)
5 Points for clean up
Total= 35 pts