Lab 7 – Cellular Respiration
Objectives
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

Measure and evaluate blood pressure readings
Examine fitness level by performing a Harvard Step test
Compare effectiveness of aerobic cellular respiration and fermentation
Introduction
How do your muscles get energy to enable you to perform strenuous activities? Muscles
must receive a constant supply of energy. Our muscles use energy that has been extracted from
the foods we consume. Many parts of our body are involved in this precisely detailed and wellchoreographed process known as energy metabolism. Our lungs bring oxygen into the body and
our heart pumps blood through miles of blood vessels to deliver nutrients and oxygen to every
cell in our body. This enables our muscle cells to contract, allowing us to perform a range of
activities from pushing the remote control button to running a marathon.
Blood pressure and heart rate changes that occur during and after exercise provide a good
indication of measuring one’s overall cardiovascular fitness. You will be performing a variation
of the Harvard step test, which is a quick way to compare the relative fitness level of a group of
people.
Remember the last time you were almost in a car accident? Your body responded to the
stressful situation in a number of ways. Your mouth may have become dry, your breathing
deepened, and your heart rate increased. Why? Your body transferred most of its efforts to
prepare for either flight or fight! The human heart is coordinated with the physiological
demands of the body, slowing down and accelerating to deliver blood based on metabolic needs.
The heart rate increases as much as 4 times under extreme physical and emotional demands to
increase blood flow to different parts of the body.
Your heart plays a vital role in transporting glucose and oxygen to every cell in your
body. Both glucose and oxygen are necessary for the production of adenosine triphosphate
(ATP) through aerobic cellular respiration. ATP is needed for almost every kind of work that
takes place in your body, including muscle contraction. The heart beats faster sending glucose
and oxygen to all your cells and to itself.
Heart attack is the death of the cardiac muscle and the resulting failure of the heart to
deliver enough blood to the rest of the body. A heart blockage is called angina. Angina occurs
when the heart is laboring hard because of emotional or physical stress. It is a signal that part of
the heart is not receiving enough oxygen.
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Lab 7 – Cellular Respiration
Heart Rate
Your heart rate tells you how many times your heart beats, or contracts, in one minute.
The term pulse refers to the alternating surges of pressure (expansion and then recoil) in an artery
that occurs with each contraction and relaxation of the left ventricle. Normally the pulse rate
(pressure surges per minute) equals the heart rate (beats per minute), and the pulse averages 70 to
76 beats per minute in the resting stage. Normal heart rate is 60 –100 beats per minute.
Blood Pressure
Blood pressure is measured in millimeters of mercury (just like weather pressure
systems!). The higher number indicates systolic pressure, which is the amount of force exerted
on the walls of the arteries within and leading from the heart when it contracts (i.e., during
systole). The lower number is the diastolic pressure, which is the force existing between
contractions (i.e., during diastole).
7.1 What’s your blood pressure?
1.
2.
3.
4.
Familiarize yourself with the pulse and blood pressure monitor.
Have someone else take your blood pressure as you SIT quietly with your left arm (the
one in the cuff) on the table.
During the test, try NOT to laugh, move, or talk.
Record values in Table 1 on QUESTIONS page.
7.2 How fit are you?
Any student with a known heart problem can refuse to participate as the subject.
1.
BEFORE doing this exercising experiment, answer the prediction questions on the
QUESTIONS page.
2.
The equipment required for this experiment include a Vernier LabPro, a receiver, one set
of hand grips, a step stool, and a timer.
a. Plug the Vernier LabPro into the outlet on the lab table. The LabPro should already
be connected to the computer.
b. The receiver (rectangular, about 2.5 cm long) is also connected to the LabPro. This
may have been done for you already.
c. Obtain a step stool (under the goggles cabinet) and flush the step stool against a solid
object, such as a cabinet or support structure. Important: the step stool must not
slide when you step on it -- for your safety. [Ideally, the step should be 45 cm, 50
cm, or 50.8 cm high.]
d. Eventually, you will be holding the hand grips and stepping on the step stool. Make
sure that the hand grips would be within 80.0 cm (or 2.62 ft) of the receiver.
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Lab 7 – Cellular Respiration
3.
The following directions will guide you to open and start the Logger Pro software.
a. If there is an icon on the desktop that says “Logger Pro 3.8.2,” double click it and
skip to Step f. If there is no icon continue with Step b.
b.
c.
d.
e.
Click Start menu (Windows icon) in lower left corner of bottom toolbar.
Click on “All Programs.”
Scroll down to and click on “Vernier Software.”
Click on “Logger Pro 3.8.2.” Do NOT choose “Quick Reference” or “Release
Notes.”
Select “File” on the upper left toolbar.
Click “Open.”
Select “Biology with Vernier” folder.
Scroll down, select, and open “27 Heart Rate and Fitness” folder.
Click OK on Page Information about the 30 sec delay before the first point is plotted.
Select Experiment tab on the toolbar at top. Choose Connect Interface, LabPro
COM 1, then click Connect.
l. You should now see a green “Collect” button added to the toolbar.
f.
g.
h.
i.
j.
k.
4.
5.
Hold the hand grips following the palm and finger configurations on the hand grips.
Reminder: make sure that the step stool, you, and the hand grips are within 80.0 cm (or
2.62 ft) of the receiver.
a. During the experiment, if you begin to get unusual data on the screen, confirm that
the hand grips are within the appropriate range of the receiver.
6.
YOU MUST HOLD ONTO THE HAND GRIPS FOR THE ENTIRE
EXPERIMENT!!!!!
7.
8.
9.
10.
When you are ready, hold the hand grips and stand in front of the step stool.
Have a partner click Collect on the program AND start the timer AT THE SAME TIME.
STAND QUIETLY FOR EXACTLY 1 MINUTE. Confirm the 1 minute using the timer.
At exactly 1 minute, place one foot on the step. Place the other foot on the step so that
both feet are on the step. Straighten your legs and back. Step down with one foot. Bring
the other foot down. Repeat. Ideally, the pace that each “Up Up Down Down” sequence
takes is 2 sec (i.e., 30 steps/min).
You should perform the stepping for 5 minutes. You should be watched and warned
against crouching (posture must remain erect).
11.
12.
13.
14.
15.
If you cannot perform the exercise for 5 minutes, you should stop when you feel you
should stop. Record how long you did exercise. Sit down and go to Step 17.
If you can perform the exercise for 5 minutes, go to Step 14.
When you have stepped up and down for 5 minutes, sit down.
REMAIN HOLDING onto the hand grips. Remember: do not go farther than 80.0 cm (or
2.62 ft) away from the receiver.
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Lab 7 – Cellular Respiration
16.
Sit until you see some data points beyond 9 minutes. Then have a partner click STOP.
Go to Step 19.
17.
REMAIN HOLDING onto the hand grips. Remember: do not go farther than 80.0 cm (or
2.62 ft) away from the receiver.
Sit for at least 4 more minutes and let the heart rate monitor read your recovery heart rate.
Then have a partner click STOP. Go to Step 19.
18.
19.
20.
21.
22.
23.
24.
25.
26.
To fill in Table 3 on QUESTIONS page, click on the graph somewhere to make sure that
the graph is highlighted and is selected.
On the toolbar, select Examine button, which is a button with X=? on it.
To obtain the “HR rest” heartbeats per minute, drag the vertical cursor to 1 minute and
read the value.
To obtain the “HR 1” (1 minute after exercise) heartbeats per minute, drag the vertical
cursor to 7 minute and read the value. [If you had to stop exercising before the 5 minutes
was up, you have to read the value that is 1 minute after the time you stopped exercising.]
To obtain the “HR 2” (2 minutes after exercise) heartbeats per minute, drag the vertical
cursor to 8 minute and read the value. [If you had to stop exercising before the 5 minutes
was up, you have to read the value that is 2 minutes after the time you stopped
exercising.]
To obtain the “HR 3” (3 minutes after exercise) heartbeats per minute, drag the vertical
cursor to 9 minute and read the value. [If you had to stop exercising before the 5 minutes
was up, you have to read the value that is 3 minutes after the time you stopped
exercising.]
Ask instructor to come over and view your graph.
Repeat the testing procedure for all students in the group.
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Lab 7 – Cellular Respiration
7.1 QUESTIONS
1.
Complete Table 1 below for the blood pressure of all group members.
Table 1. Blood pressure at rest.
Person 1
Person 2
Person 3
Person 4
Average
Blood pressure
(systolic/diastolic)
The table below shows the various “categories” of blood pressure. If your blood pressure
is too high, you may be in danger of having a heart attack, stroke, or some other form of
disorder.
Blood Pressure (in millimeters of mercury)
Normal
Systolic: < 130
Diastolic: < 85
High Normal
Systolic: 130139
Diastolic: 85-89
Mild High
Systolic: 140159
Diastolic: 90-99
Example: 120/84
Example: 135/85
Example: 145-95
2.
Moderate High
Systolic: 160179
Diastolic: 100109
Example:
160/105
Severe High
Systolic: 180+
Diastolic: 110+
Example:
180/115
Complete Table 2 below to indicate the category that each person’s blood pressure values
fall into. (see Blood Pressure Table above)
Table 2. Blood pressure categories.
Person 1
Person 2
Person 3
Person 4
Blood pressure
category
3.
The blood pressure values and categories in the above tables may not be as accurate as
measurements taken at the doctor’s office. Provide two possible reasons why these
numbers may not be accurate.
4.
How would smoking affect blood pressure values at rest?
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Lab 7 – Cellular Respiration
7.2 QUESTIONS
5.
Before doing the exercising experiment,
a. what is your prediction of how heart rate will change at one minute after exercising?
b. what is your prediction of heart rate values at three minutes after exercising?
6.
Complete Table 3 below to show how heart rates changed after exercising and while
resting after exercising.
Table 3. Heart rate (HR) influenced by exercise.
Person 1
Person 2
Person 3
Person 4
Average
HR rest
(0 min)
HR 1
(1 min after exercise)
HR 2
(2 min after exercise)
HR 3
(3 min after exercise)
Fitness index
(question #8)
7.
Show each group member’s graph to the instructor.
8.
Physical fitness index may be calculated according to the following formula.
Index = duration of exercise in seconds X 100
2 X sum of the 3 pulse counts in recovery
Calculate the fitness index for each group member and place the values in Table 3 above.
For your interest, index scores are interpreted according to the following scale:
Condition
Fitness Index
excellent
> 90
good
80 - 89
high average
65 - 79
low average
55 - 64
poor
< 55
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Lab 7 – Cellular Respiration
9.
Based on averaged values for your group shown in Table 3, explain if your results for
heart rates support or do not support your predictions in question # 5.
10.
Provide two ways that the stepping experiment could have been improved or you can
discuss errors that may have been made.
HAND IN QUESTIONS PAGES 5-7.
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