Part 1 - Get a Lab Appointment and Install Software:
Set up an Account on the Scheduler (FIRST TIME USING NANSLO):
Find the email from your instructor with the URL (link) to sign up at the scheduler.
Set up your scheduling system account and schedule your lab appointment.
NOTE: You cannot make an appointment until two weeks prior to the start date of this lab assignment.
You can get your username and password from your email to schedule within this time frame.
Install the Citrix software: – go to http://receiver.citrix.com and click
download > accept > run > install (FIRST TIME USING NANSLO).
You only have to do this ONCE. Do NOT open it after installing. It will work automatically when you go
to your lab. (more info at
http://www.wiche.edu/info/nanslo/creative_science/Installing_Citrix_Receiver_Program.pdf)
Scheduling Additional Lab Appointments:
Get your scheduler account username and password from your email.
Go to the URL (link) given to you by your instructor and set up your appointment.
(more info at http://www.wiche.edu/nanslo/creative-science-solutions/students-scheduling-labs)
Changing Your Scheduled Lab Appointment:
Get your scheduler account username and password from your email. Go to http://scheduler.nanslo.org
and select the “I am a student” button. Log in to go to the student dashboard and modify your
appointment time. (more info at http://www.wiche.edu/nanslo/creative-science-solutions/studentsscheduling-labs)
Part 2 – Before Lab Day:
Read your lab experiment background and procedure below, pages 1-14.
Submit your completed Pre-Lab 1-4 Questions (pages 7-9) per your faculty’s instructions.
Watch the Photosynthesis Control Panel Video Tutorial
http://www.wiche.edu/nanslo/lab-tutorials#photosynthesis
Part 3 – Lab Day
Log in to your lab session – 2 options:
1)Retrieve your email from the scheduler with your appointment info or
2) Log in to the student dashboard and join your session by going to http://scheduler.nanslo.org
NOTE: You cannot log in to your session before the date and start time of your appointment. Use
Internet Explorer or Firefox.
Click on the yellow button on the bottom of the screen and follow the instructions to talk to your lab
partners and the lab tech.
Remote Lab Activity
SUBJECT SEMESTER: ____________
TITLE OF LAB: Photosynthesis
Lab format: This lab is a remote lab activity.
Relationship to theory (if appropriate): In this lab you will be examining the underlying
processes of photosynthesis.
Instructions for Instructors: This protocol is written under an open source CC BY license. You
may use the procedure as is or modify as necessary for your class. Be sure to let your students
know if they should complete optional exercises in this lab procedure as lab technicians will not
know if you want your students to complete optional exercise.
Instructions for Students: Read the complete laboratory procedure before coming to lab.
Under the experimental sections, complete all pre-lab materials before logging on to the
remote lab, complete data collection sections during your on-line period, and answer questions
in analysis sections after your on-line period. Your instructor will let you know if you are
required to complete any optional exercises in this lab.
Remote Resources: Primary - Microscope; Secondary – Light Sources.
CONTENTS FOR THIS NANSLO LAB ACTIVITY:
Learning Objectives....................................................................................................... 2
Background Information .............................................................................................. 2-7
Pre-lab Exercise 1: Measuring O2 Levels as a Function of
Photosynthesis Rates - Qualitative ........................................................................... 7-8
Pre-lab Exercise 2: Measuring O2 Levels as a Function of
Photosynthesis Rates - Quantitative ......................................................................... 8
Pre-lab Exercise 3: The Effect of Wavelength of Light on
Photosynthetic Rates ................................................................................................ 9
Pre-lab Exercise 4: The Effects of Temperature on Photosynthesis ........................... 9
Equipment .................................................................................................................... 9
Preparing for this NANSLO Lab Activity ....................................................................... 10
Experimental Procedure .............................................................................................. 10
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CONTENTS FOR THIS NANSLO LAB ACTIVITY – CON’TD
Exercise 1: Measuring O2 Levels as a Function of
Photosynthesis Rates - Qualitative ........................................................................... 10-11
Exercise 2: Measuring O2 Levels as a Function of
Photosynthesis Rates - Quantitative .........................................................................11-12
Exercise 3: The Effect of Wavelength of Light on
Photosynthetic Rates ................................................................................................ 12
Exercise 4: The Effects of Temperature on Photosynthesis ....................................... 13
Summary Questions ..................................................................................................... 13-14
Creative Commons Licensing ....................................................................................... 14
U.S. Department of Labor Information ........................................................................ 14
LEARNING OBJECTIVES:
After completing this laboratory experiment, you should be able to do the following things:
1. State the photosynthetic equation and determine what two things you could measure
to determine the rate of photosynthesis?
2. Design and conduct a simple experiment to show the evolution of oxygen gas as a
product of photosynthesis.
3. Describe how altering a variable such as light intensity or wavelength will impact
photosynthesis.
4. Determine which wavelengths of light have high energy and which have lower energy
levels.
5. Collect quantitative data on the rate of photosynthesis at different wavelengths of light.
6. Graph the data collected and interpret the data.
7. Explain why the rate of photosynthesis varies under different environmental conditions.
8. Use an O2 Gas Sensor to measure the amount of oxygen gas consumed or produced by a
plant during respiration and photosynthesis.
9. Use a CO2 Gas Sensor to measure the amount of carbon dioxide consumed or produced
by a plant during respiration and photosynthesis.
BACKGROUND INFORMATION:
Photosynthesis is a process carried out by green plants and photosynthetic bacteria. These
organisms use the suns light energy to make food they are called autotrophic which means that
they are “self-feeders.” Autotrophic organisms convert inorganic carbon derived from CO2 to
organic carbon contained in the glucose molecule. The glucose molecule is then used as a
chemical energy source for the plants and other organisms. The energy captured by autotrophic
organisms through the process of photosynthesis provides the basis for the food chain.
Approximately 1% of the sun’s energy that reaches earth is captured by plants and other
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Figure 1: Photosynthesis
Overview
photosynthetic organisms. In Figure 1 you can see that
the light energy, carbon dioxide and water are the
reactants of the photosynthetic process while oxygen
is released back to the atmosphere. The glucose
produced remains in the plant.
Photosynthesis takes place primarily in the leaves of a
plant but any plant structure with chloroplasts has the
ability to undergo photosynthesis. The components of
chloroplasts are shown in Figure 2. In the cross section
of the leaf you can see the green representation of the
chloroplasts in the upper epidermis. Then the view of
the chloroplast and finally the structure of the
thylakoid as it is stacked forming grana (plural
granum).
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THYLAKOIDS – flattened membrane
sacs within the chloroplast. The
thylakoid membranes contain the
chlorophyll and other pigment
molecules.
GRANUM – columns of thylakoids
stacked on top of one another.
STROMA – the liquid substances
surrounding the thylakoid
membrane system.
Figure 2: Leaf Cross Section and
Chloroplast Struc
The Stages of photosynthesis are broken
into the Light Dependent or light reactions
and Light Independent or Dark
ture
reactions/Calvin cycle systems. The light dependent cycle captures energy from sunlight and
uses that energy to make ATP. The light independent cycle uses the ATP from the light
dependent cycle to power the synthesis of carbon molecules (glucose) from CO2 in the air
(Calvin Cycle).
Overall the balanced equation for photosynthesis is:
6 CO2 + 12 H2O + light energy → C6H12O6 (glucose) + 6 O2
Light and Photosynthesis – Light from the sun is emitted as electromagnetic radiation or solar
energy. When referring to all of the forms of electromagnetic radiation it is called the
electromagnetic spectrum (see Figure 3). Visible light is the range of the electromagnetic
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spectrum that we can see. Light energy travels in and is measured in waves. Each wave is
measured from crest to crest and has a specific length called the wavelength. Different
wavelengths correspond to different amounts of energy carried. A long wavelength carries less
energy than a short wavelength so as you look at Figure 3 you can see that the high energy
waves like X –rays and UV rays are shorter in length then the lower energy waves like radio
waves are longer in length. The visible light range is made up of wavelengths that are
intermediate in length. As a group these wavelengths are considered to be white light but if you
were to separate these wavelengths you would see the rainbow of colors.
In terms of photosynthesis when the light energy from the sun hits a plant the pigments
Figure 3: The Electromagnetic Spectrum
(chlorophyll and other accessory molecules) absorb the
energy from the light. The light is absorbed in a “packet”
of energy or a photon. A photon of light energy will be
absorbed by a molecule of chlorophyll, the photon
causes the chlorophylls electrons to become “excited”
and move from the chlorophyll molecule to a carrier
molecule (electron acceptor) that can “hold” the high
energy electron. There are several different pigments in
plants each different pigment will absorb a specific
wavelength of light so not all wavelengths of light will
result in the same photosynthetic rate. Figure 4 shows
the two primary photosynthetic pigments chlorophyll a
and chlorophyll b and the absorbance of light.
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Figure 4: Absorbance of
Chlorophyll a and Chlorophyll b
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Events in the Photosynthetic Pathway
1. Light Dependent Reactions - Light-capturing events of photosynthesis require light energy
from the sun. The sun light energy is carried in photons and will be absorbed one photon at a
time by a collection of pigment molecules called a photosystem. Light dependent
photosynthetic reactions use photosystem II (named based on the order of discovery). The
chlorophyll molecules electrons absorb the light energy which boosts the electrons to higher
energy states. These excited electrons provide the energy for two things: a) to make ATP, and
b) to split water into hydrogen protons, electrons and oxygen (which is released into the air)
this process is called PHOTOLYSIS. The protons from the hydrogen are transferred to the
electron carrier coenzyme NADP+ to ultimately produce NADPH. The ATP and the NADPH
move from the grana to the stroma where the lightindependent reactions take place.
Figure 5: Photosystem II – Light
Light energy + H2O + ADP + NADP+ → ATP + NADPH + O2
Dependent Reactions
Photosystem II
In Figure 5 you can follow the light dependent reactions;
light energy splits a water molecule, this provides electrons
from the water molecule which move through the
photosystem, the released oxygen atom joins with another
to be released to the atmosphere as O2. The hydrogen
protons travel through the system and end up rejoining with
the electrons to recreate the 2 hydrogen atoms that are
required to form NADPH from NADP+. The electron from
photosystem II now having lost the energy gained from the
light energy can be accepted by a chlorophyll molecule at
photosystem I (remember named based on order of
discovery not order of activity) and re-energized by the light
from the sun and begin a
Figure 6: The path of electrons from PSII to PSI and the
second energized transport
formation of ATP and NADPH
from protein carrier to
protein carrier.
Lastly, some of the energy
from the excited electrons is
used to generate ATP from
ADP. It is important to
realize that the main role of
the light reactions is to
capture the light energy and
create the energy carriers
ATP and NADPH which will
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then be used in the light independent (Dark reaction or Calvin Cycle) reactions. Figure 6 shows
the flow of the electrons from Photosystem II where they first become “excited” through the
series of proteins forming an electron transport chain to their arrival at Photosystem I where
they are reenergized by light energy and passed to proteins that use the energy to create ATP
and NADPH.
2. Light-independent events (Calvin Cycle)
The ATP and NADPH produced in the light dependent reactions are also used in this stage to
build large, organic molecules from carbon dioxide. These are a series of oxidation-reduction
reactions passing the electrons from protein to protein in the thylakoid membrane to ultimately
form glucose. As CO2 diffuses into the chloroplasts from the atmosphere, the enzyme ribulose
biphosphate carboxylase (RuBisCo) speeds the combining of the CO2 with an already present, 5carbon carbohydrate, ribulose in the stroma see Figure 7. The reaction is:
ATP+ NADPH + ribulose + CO2 → ADP + NADP+ + complex organic molecule (glucose
precursor) + ribulose
Note that the ADP, NADP+ and ribulose
are recycled to keep the cycle of
photosynthesis going.
Figure 7: The Light Independent Reaction
or Calvin Cycle
During photosynthesis, plants will use
water and carbon dioxide and convert
them into glucose and oxygen. At the
same time as this is going on the plants
are also undergoing cellular respiration.
This process is actually the reverse of
photosynthesis because it will release
carbon dioxide and water while
consuming glucose and oxygen.
Summary- Recall the process of
photosynthesis involves the use of light
energy to convert carbon dioxide and
water into sugar, oxygen, and other
organic compounds. Review the following reaction:
6 H2O + 6 CO2 + light energy → C6H12O6 + 6 O2
This process is an extremely complex one, occurring in two stages. The first stage, called the
light dependent cycle of photosynthesis, requires light energy. The products of the light
dependent cycle are then used to produce glucose from carbon dioxide and water. Because the
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reactions in the second stage do not require the direct use of light energy, they are called the
light independent cycle of photosynthesis. In the light reactions, electrons derived from water
are “excited” (raised to higher energy state) in several steps, called photosystems I and II. In
both steps, chlorophyll absorbs light energy that is used to excite the electrons. Normally, these
electrons are passed to a cytochrome containing an electron transport chain. In the first
photosystem, these electrons are used to generate ATP. In the second photosystem, excited
electrons are used to produce the reduced coenzyme nicotinamide adenine dinucleotide
phosphate (NADPH). Both ATP and NADPH are then used in the dark reactions to produce
glucose. The glucose can then be used in cellular respiration or stored as a starch.
Light is part of the electromagnetic spectrum it is measured in wavelengths and absorbed by a
plant pigment as a photon or packet of energy. Plants contain pigments such as chlorophylls. A
pigment is any substance that absorbs light. The color of the pigment comes from the
wavelengths of light reflected (in other words, those not absorbed). Chlorophylls, the green
pigments common to all photosynthetic cells, absorbs all wavelengths of visible light except
green, which it reflects to be detected by our eyes.
In this lab, we will be using gas probes to quantitatively measure the rate of photosynthesis.
There are both qualitative and quantitative methods that can be used to record and observe
photosynthesis. Qualitative data are based on the 5 senses: what does it look like, smell like or
feel like? Quantitative data on the other hand are measured and numerical.
References
Figures 2 -7: http://www.ncbi.nlm.nih.gov/books/NBK26819/figure/A2564/?report=objectonly
Figure 8: http://www.oceanoptics.com/Products/benchoptions_usb4.asp
PRE-LAB EXERCISE 1: Measuring O2 Levels as a Function of
Photosynthetic Rates – Qualitative
Recall the equation and information from above you will use this to help you understand what
gas will be produced as an end product of photosynthesis. By observing the production of a gas
we can indirectly measure the rate of photosynthesis. Exercise 1 will allow you to design your
own simple experiment to indirectly measure the rate of photosynthesis.
There are several ways one can observe the process of photosynthesis; we are going to focus
on designing a simple experiment to observe the production of oxygen gas as the light energy
hits the plant.
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Supplies: This is meant to give you some guidelines but you can be as creative as you wish.
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Baking soda- . To create a bicarbonate solution, add about 1/8th of a teaspoon of baking
soda to 300 mLs of water ( a little over 1 cup)
A healthy fresh picked leaf/plant. The ideal plant is the aquatic plant Anacharis (Elodea)
which can be obtained from a pet store, but you can use a leaf from any plant as long as
it is freshly picked and healthy.
A small clear glass, jar or test tube
A bright light (100 watt) that you can direct at the leaf or a sunny window.
A hand lens optional
Pre-Lab Questions:
1. What gas is produced as a product of photosynthesis? Use the photosynthetic equation
to support your answer.
2. Why is this experiment an indirect system as opposed to a direct system of measuring
the photosynthetic rate?
PRE-LAB EXERCISE 2: Measuring O2 Levels as a Function of
Photosynthetic Rates – Quantitative
The process of photosynthesis involves the use of light energy to convert carbon dioxide and
water into sugar, oxygen, and other organic compounds. By using an O2 gas sensor to measure
the amount of gas present we can determine if oxygen is being produced and at what rate and
if carbon dioxide is being consumed and at what rate. From this we can plot the rate of
photosynthesis over time as a function of the intensity of the light. A plant in the light will be
undergoing the process of photosynthesis and based on the photosynthetic equation will be
giving off oxygen.
Cellular respiration is a metabolic reaction that uses oxygen and produces carbon dioxide below
you see the simplified equation: C6H12O6 (glucose) + 6 O2 → 6 CO2 + 12 H2O + ATP. As you
conduct this lab keep in mind that while we are measuring the amount of oxygen and carbon
dioxide there are other metabolic processes that can be affecting these gases. If we measure
the gas production of a plant in the dark the rate of oxygen produced should decrease while the
rate of carbon dioxide produced should increase.
Pre-Lab Questions:
1. What information will this exercise tell you that the previous one did not?
2. Why is this kind of data important?
3. What do you expect to see with the concentration of O2 over time?
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4. Using your answer to question 3 create an IF … THEN hypotheses relating the effect of
temperature on the rate of O2 production.
PRE-LAB EXERCISE 3: The Effect of Wavelengths of Light
on Photosynthetic Rates
In Exercise 1 you collected data on photosynthetic rate of a plant going from a dark to light. In
this exercise you will be looking at the impact of specific wavelengths of light on photosynthetic
rates. Review Figure 4 and note that there are two primary types of chlorophyll. In addition
there are accessory pigments that aid in photosynthesis. To put this all into perspective think
about the colors leaves turn in the fall. This gives you an idea of the other types/colors of
pigments in plants.
Pre-Lab Questions:
1. Explain in your own words the difference between absorbance and reflection. Now
apply this to plant pigments and photosynthesis.
2. If a plant has a red leaf will it photosynthesize? Use your understanding to support your
answer.
3. What wavelengths of light would you choose to experiment with and why?
4. Hypothesis/Prediction – Set this up as an - If … THEN hypotheses. For example: If the
correct wavelength of light is shone on a plant then observable differences will be seen
in the rate of photosynthesis.
PRE-LAB EXERCISE 4: The Effect of Temperature on Photosynthesis
In this exercise we are going to examine the effects of temperature on the rate of
photosynthesis.
Pre-lab Questions:
1. What parts of the photosynthetic process might be effected by temperature? Why
2. Using your answer to question one create an” If Then” hypothesis relating the effect of
temperature on the rate of O2 production.
EQUIPMENT:
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Paper
Pencil/pen
Computer with Internet access (for the remote laboratory and for data analysis)
For Pre-lab Exercise 1 – Baking soda, Anacharis (elodea) or a healthy plant, Small clear glass, 10
Watt light, hand lens
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PREPARING FOR THIS NANSLO LAB ACTIVITY:
Read and understand the information below before you proceed with the lab!
Scheduling an Appointment Using the NANSLO Scheduling System
Your instructor has reserved a block of time through the NANSLO Scheduling System for you to
complete this activity. For more information on how to set up a time to access this NANSLO lab
activity, see www.wiche.edu/nanslo/scheduling-software.
Students Accessing a NANSLO Lab Activity for the First Time
For those accessing a NANSLO laboratory for the first time, you may need to install software on
your computer to access the NANSLO lab activity. Use this link for detailed instructions on
steps to complete prior to accessing your assigned NANSLO lab activity –
www.wiche.edu/nanslo/lab-tutorials.
Video Tutorial for RWSL: A short video demonstrating how to use the Remote Web-based
Science Lab (RWSL) control panel for the air track can be viewed at
http://www.wiche.edu/nanslo/lab-tutorials#photosynthesis.
NOTE: Disregard the conference number in this video tutorial.
AS SOON AS YOU CONNECT TO THE RWSL CONTROL PANEL: Click on the yellow button at the
bottom of the screen (you may need to scroll down to see it). Follow the directions on the pop
up window to join the voice conference and talk to your group and the Lab Technician.
EXPERIMENTAL PROCEDURE:
Once you have logged on to the microscope you will perform the following Laboratory procedure:
EXERCISE 1: Measuring O2 Levels as a Function of Photosynthetic
Rates – Qualitative
Data Collection:
The idea here is for you to set up an experiment to visualize the oxygen production as a result
of photosynthesis. There are a great many resources on the web so do some background
research and design your experiment. For the pre lab you will need to take photos of your
experiment as well as write out your Purpose, Hypothesis, Methods, Results/Data and
Conclusions. Please remember to cite any sources you used to help you plan your experiment.
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1. Write out your experimental design
2. Build your experimental apparatus, and photograph it.
3. Record your observations in your data table
Analysis:
4. Write a lab report on the pre lab experiment. Your report should include: Purpose,
Hypothesis, Methods, Results/Data, Conclusions and any sources you used.
5. What you would have changed in your experiment to improve on it and how would your
suggestion have made the experiment better?
6. How could you use the same basic approach and test for the effect of wavelengths of
light on photosynthesis?
7. Did your experiment have a control? If not suggest what you could have done to create
a control.
8. What was the function of adding the sodium bicarbonate to the solution?
9. Read the introduction to Exercise 1 and write a Hypothesis Prediction in the form of an
If … THEN hypotheses for the Remote lab activity.
EXERCISE 2: Measuring O2 Levels as a Function of Photosynthetic
Rates – Quantitative
Data Collection:
1. Click the temperature tab set the temperature to 27 ° C. Wait for the temperature to
stabilize.
2. Click the graph tab; click the start recording button for the gas probes.
3. Record your data for 10 minutes.
4. Record the light intensity.
5. Click the light source tab and turn on the “normal” light (record the time you turn on the
light).
6. Record your data for another 10 minutes.
7. Record the light intensity.
8. Click the graph tab; click the stop recording button for the gas probes.
9. Click the export data button to export the gas and temperature data.
Analysis (can be done offline):
10. Create a data table to record the O2 rates over a 20 minute period starting in the dark
and then turning the light on.
11. Using the data create a graph of gas concentrations vs time.
12. Do you have evidence that photosynthesis occurred? Explain.
13. How did the oxygen levels change when the plant was in darkness?
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14. How did exposure to light affect the oxygen levels in the container?
15. Make a claim about what you learned and back it up with the data or evidence you
gathered. You may have more than one claim and evidence statement.
16. Think back to the initial hypothesis you made, was your prediction correct? Write a
statement that uses your data to either support or reject your hypothesis.
EXERCISE 3: The Effect of Wavelengths of Light on Photosynthetic Rates
Data Collection:
1. Click the temperature tab set the temperature to 27 ° C. Wait for the temperature to
stabilize.
2. Click the graph tab; click the start recording button for the gas probes.
3. Click the light source tab and turn on the “normal” light (record the time you turn on the
light)
4. Record your data for 10 minutes.
5. Record the light intensity.
6. Click the graph tab; click the stop recording button for the gas probes.
7. Click the export data button to export the gas and temperature data.
8. Click the light source tab select the Green light repeat steps 2-7.
9. Click the light source tab select the Red light repeat steps 1-7.
10. Click the light source tab select the Yellow light repeat steps 1-7.
11. Click the light source tab select the Blue light repeat steps 1-7.
Analysis (can be done offline):
12. Create a data table to record the O2 production rates for white, Green, Red, Yellow, and
Blue lights.
13. Using the data plot a graph that shows the rate of O2 production vs time at the different
wavelengths of light.
14. If the rate of O2 production is low what does that tell you about the effectiveness of that
wavelength of light? What if the rate of O2 production is high?
15. Make a claim about what you learned and back it up with the data or evidence you
gathered. You may have more than one claim and evidence statement.
16. Think back to the initial hypothesis you made, was your prediction correct? Write a
statement that uses your data to either support or reject your hypothesis.
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EXERCISE 4: The Effect of Temperature on Photosynthesis
Data Collection:
1. Click the temperature tab select a temperature below 27 ° C. Wait for the temperature
to stabilize.
2. Click the graph tab; click the start recording button for the gas probes.
3. Click the light source tab and turn on the “normal” light (record the time you turn on the
light)
4. Record your data for 10 minutes.
5. Record the light intensity.
6. Click the graph tab; click the stop recording button for the gas probes.
7. Click the export data button to export the gas and temperature data.
8. Repeat steps 1-6 with a different temperature below 27 ° C.
9. Repeat steps 1-6 with a different temperature above 27 ° C.
10. Repeat steps 1-6 with a different temperature above 27 ° C.
Analysis:
11. Create a data table to record the O2 production rates vs time for your four different
temperatures.
12. Using the data plot a graph that shows the rate of O2 production vs time at the different
temperatures.
13. What affect did temperature have on O2 production?
14. Make a claim about what you learned and back it up with the data or evidence you
gathered. You may have more than one claim and evidence statement.
15. Think back to the initial hypothesis/prediction you made, was your prediction correct?
Write a statement that uses your data to either support or reject your hypothesis.
SUMMARY QUESTIONS:
1. List two additional factors that might influence the rate of oxygen production or
consumption in leaves and explain how you think each will affect the rate?
2. Design an experiment to test one of the factors that might influence the rate of oxygen
production or consumption. Write out a hypothesis for the experiment.
3. Plants grow in all types of environmental conditions shade /sun, dry/moist, research and
compare the rates of photosynthesis among various types of plants.
4. What might be the benefit of having different types of chlorophylls and accessory
pigments for a plant?
5. A more meaningful way to report the rate of photosynthesis is in µmol O2 m-2 min-1 That
is, the actual amount of O2 produced per unit of leaf area per unit time. Calculate the
rate of photosynthesis in µmol m-2 min-1
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The following information will be helpful:
1% O2 = 10,000 µL O/ L gas. The volume of the chamber is 8L
At standard temperature and pressure 1 µmol of a gas has a volume of 22.4 µL you will
also need to measure the area of the leaf that you used in the chamber.
6. In Exercise 1 you measured the photosynthetic rate O2 produced in light and then in the
dark. Relate these values to the processes of photosynthesis and respiration.
For more information about NANSLO, visit www.wiche.edu/nanslo.
All material produced subject to:
Creative Commons Attribution 3.0 United States License 3
This product was funded by a grant awarded by the U.S.
Department of Labor’s Employment and Training Administration.
The product was created by the grantee and does not necessarily
reflect the official position of the U.S. Department of Labor. The
Department of Labor makes no guarantees, warranties, or
assurances of any kind, express or implied, with respect to such
information, including any information on linked sites and
including, but not limited to, accuracy of the information or its
completeness, timeliness, usefulness, adequacy, continued
availability, or ownership.
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