The document discusses data logging and the use of gas sensors to measure oxygen and carbon dioxide levels during photosynthesis experiments. It provides detailed procedures for setting up oxygen and carbon dioxide sensors and using a datalogger to collect readings over time from the sensors placed near plant leaves. The procedures describe taking readings from the sensors in both light and dark conditions, and using the datalogged data to calculate respiration and photosynthesis rates from the slopes of oxygen and carbon dioxide graphs.
Linear attenuation coefficient (휇) is a measure of the ability of a medium to diffuse and absorb radiation. In the interaction of radiation with matter, the linear absorption coefficient plays an important role because during the passage of radiation through a medium, its absorption depends on the wavelength of the radiation and the thickness and nature of the medium. Experiments to determine linear absorption coefficient for Lead, Copper and Aluminum were carried out in air. The result showed that linear absorption Coefficient for Lead is 0.545cm – 1, Copper is 0.139cm-1 and Aluminum is 0.271cm-1 using gamma-rays. The results agree with standard values.
Linear attenuation coefficient (휇) is a measure of the ability of a medium to diffuse and absorb radiation. In the interaction of radiation with matter, the linear absorption coefficient plays an important role because during the passage of radiation through a medium, its absorption depends on the wavelength of the radiation and the thickness and nature of the medium. Experiments to determine linear absorption coefficient for Lead, Copper and Aluminum were carried out in air. The result showed that linear absorption Coefficient for Lead is 0.545cm – 1, Copper is 0.139cm-1 and Aluminum is 0.271cm-1 using gamma-rays. The results agree with standard values.
Description of nuclear half-life and practice calculations. Adapted from http://www.teachnlearnchem.com/SPANISH/Equations%20PP/SpanNuclear%20Equations.ppt
PHOTOCATALYTIC DEGRADATION AND REMOVAL OF HEAVY METALS IN PHARMACEUTICAL WAST...Journal For Research
In recent years pharmaceutical wastes (PW) deposal of has become a major difficulty for the environment. Therefore, pharmaceutical waste removal is very necessary before its discharge from the pharma industry. The separation of drugs containing organic compounds in wastewater streams is failed by convectional and biological treatments. Thus, the reduction of harmful effects of pharmaceutical compounds is possible by heterogeneous photocatalysis process. Herein we reported the degradation of pharmaceutical concentration in pharmaceutical waste by heterogeneous photocatalyst ZnO doped with Selenium prepared by cost effective hydrothermal method. In addition the heavy metals in pharmaceutical waste were also removed by ZnO/Se nanocomposite. The average band gap of nanocomposite (~2.5 eV) increase the photocatalytic activity and degrade the organic compounds in pharmaceutical waste. The heavy metals get adsorbed on the high surface area of nanocomposite and removed completely by filtration method. The Selenium doped ZnO photocatalyst semiconductor was characterized by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDAX) and also the characteristic crystalline forms of ZnO/Se nanocomposite was confirmed by XRD. The functional groups and particle size distribution of ZnO/Se nanocomposite was characterized by FTIR and DLS respectively. The reduction of organic compounds in the pharmaceutical waste was confirmed by COD analysis and removal of heavy metals was performed by AAS analysis.
GCSE Chemistry Revision - Air and Air PollutionKatie B
This is a quick summary of the GCSE Chemistry topic around the atmosphere and air pollution. It includes topics on acid rain, nitrogen oxides, global warming and car pollution. I have used the Letts GCSE in a Week book for most of this presentation.
In Earth science, a biogeochemical cycle or substance turnover or cycling of substances is a pathway by which a chemical substance moves through both the biotic (biosphere) and abiotic (lithosphere, atmosphere, and hydrosphere) components of Earth.
Post-combustion CO2 capture from natural gas combined cycles by solvent supported membranes - presentation by Matteo Romano of Politecnico di Milano at the UKCCSRC Natural Gas CCS Network Meeting at GHGT-12, Austin, Texas, October 2014
more chemistry contents are available
1. pdf file on Termmate: https://www.termmate.com/rabia.aziz
2. YouTube: https://www.youtube.com/channel/UCKxWnNdskGHnZFS0h1QRTEA
3. Facebook: https://web.facebook.com/Chemist.Rabia.Aziz/
4. Blogger: https://chemistry-academy.blogspot.com/
Oxyacids of sulphur are sulphur, hydrogen and oxygen containing compounds. Oxyacids of sulphur are sulphurous acid, sulphuric acid, peroxomonsulphuric acid, peroxodisulphuric acid, thiosulphuric acid, dithionous acid, dithionic acid, polythionic acid and pyrosulphuric acid.
Description of nuclear half-life and practice calculations. Adapted from http://www.teachnlearnchem.com/SPANISH/Equations%20PP/SpanNuclear%20Equations.ppt
PHOTOCATALYTIC DEGRADATION AND REMOVAL OF HEAVY METALS IN PHARMACEUTICAL WAST...Journal For Research
In recent years pharmaceutical wastes (PW) deposal of has become a major difficulty for the environment. Therefore, pharmaceutical waste removal is very necessary before its discharge from the pharma industry. The separation of drugs containing organic compounds in wastewater streams is failed by convectional and biological treatments. Thus, the reduction of harmful effects of pharmaceutical compounds is possible by heterogeneous photocatalysis process. Herein we reported the degradation of pharmaceutical concentration in pharmaceutical waste by heterogeneous photocatalyst ZnO doped with Selenium prepared by cost effective hydrothermal method. In addition the heavy metals in pharmaceutical waste were also removed by ZnO/Se nanocomposite. The average band gap of nanocomposite (~2.5 eV) increase the photocatalytic activity and degrade the organic compounds in pharmaceutical waste. The heavy metals get adsorbed on the high surface area of nanocomposite and removed completely by filtration method. The Selenium doped ZnO photocatalyst semiconductor was characterized by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDAX) and also the characteristic crystalline forms of ZnO/Se nanocomposite was confirmed by XRD. The functional groups and particle size distribution of ZnO/Se nanocomposite was characterized by FTIR and DLS respectively. The reduction of organic compounds in the pharmaceutical waste was confirmed by COD analysis and removal of heavy metals was performed by AAS analysis.
GCSE Chemistry Revision - Air and Air PollutionKatie B
This is a quick summary of the GCSE Chemistry topic around the atmosphere and air pollution. It includes topics on acid rain, nitrogen oxides, global warming and car pollution. I have used the Letts GCSE in a Week book for most of this presentation.
In Earth science, a biogeochemical cycle or substance turnover or cycling of substances is a pathway by which a chemical substance moves through both the biotic (biosphere) and abiotic (lithosphere, atmosphere, and hydrosphere) components of Earth.
Post-combustion CO2 capture from natural gas combined cycles by solvent supported membranes - presentation by Matteo Romano of Politecnico di Milano at the UKCCSRC Natural Gas CCS Network Meeting at GHGT-12, Austin, Texas, October 2014
more chemistry contents are available
1. pdf file on Termmate: https://www.termmate.com/rabia.aziz
2. YouTube: https://www.youtube.com/channel/UCKxWnNdskGHnZFS0h1QRTEA
3. Facebook: https://web.facebook.com/Chemist.Rabia.Aziz/
4. Blogger: https://chemistry-academy.blogspot.com/
Oxyacids of sulphur are sulphur, hydrogen and oxygen containing compounds. Oxyacids of sulphur are sulphurous acid, sulphuric acid, peroxomonsulphuric acid, peroxodisulphuric acid, thiosulphuric acid, dithionous acid, dithionic acid, polythionic acid and pyrosulphuric acid.
1 Objectives • Measure carbon dioxide evolution and .docxjoyjonna282
1
Objectives
• Measure carbon dioxide evolution and
uptake in plants and animals.
• Study the effect of temperature on cell
respiration.
• compare respiration rates in germinating
and non-germinating peas.
Introduction
Energy is required by living organisms for
movement, transport, and growth. Nothing
happens without energy! The Sun is the
ultimate source of virtually all energy on the
planet Earth. Solar energy is captured by
plants through the process of photosynthesis.
The glucose molecules holding this energy are
broken down by metabolic processes, creating
usable energy for living systems.
Cellular respiration is a series of reactions in
which glucose molecules are broken down,
releasing stored chemical bond energy
(Figure 6.1). The released energy is used to
make the energy rich molecule ATP
(adenosine triphosphate). Carbon dioxide is
released as a by-product of the breakdown of
glucose. It is a crucial by-product from the
perspective of plants, because they need CO2
to perform photosynthesis.
Glycolysis is the first step in cellular
respiration, and it results in the net production
of two ATP molecules. In glycolysis, the 6-
carbon glucose molecules are “split” into two,
3-carbon pyruvate (pyruvic acid) molecules.
LAB TOPIC 6: RESPIRATION
Pyruvate has two potential routes – aerobic
respiration or anaerobic respiration [as either
lactate fermentation or alcohol fermentation]
(Figure 6.1).
1
In laboratory today, you will be examining
respiration in organisms that use aerobic
respiration, which makes use of oxygen. In
this pathway, pyruvate is broken down
completely, and h igh-energy electrons are
stripped away and passed through a series of
electron carriers. Energy is released at each
transfer, and is used to make a net 34 ATP
molecules. Oxygen is the final electron
acceptor in the electron transport system,
hence the name aerobic cellular respiration. In
lecture you will compare this process to
anaerobic respiration, which occurs in the
absence of oxygen or under low oxygen
conditions. The equation below summarizes
the process of aerobic respiration:
C6H12O6
+
6
O2
à 6
CO2
+
6
H2O
+
ATP
+
Heat
Glucose
Oxygen
Carbon
Water
Dioxide
Considering the equation for aerobic
respiration what variables could you measure
to monitor respiration rate?
Figure
6.1
Glycolysis
and
the
potential
fates
of
pyruvate
during
cellular
respiration.
2
2
Oxygen Consumption during Aerobic
Respiration
Aerobic respiration uses oxygen as the
terminal electron‐acceptor in the electron
transport chain and produces carbon dioxide
(see equation above). You can, therefore,
monitor the respiration rate of an organism by
measuring its uptake of oxygen or evo ...
Science
Name:
Date:
Instructor’s Name:
Assignment:
Lab
Report
Title
:
Sources of CO
2
Emissions
Instructions:
You will need to write a 1-page lab report using the scientific method centered on the known phenomena of CO
2
emissions, related to the following question:
•
Would you expect to see an increase or decrease in CO
2
emission in the data over the past 40 years? Why?
When your lab report is complete, post it in Submitted Assignment files.
Part I:
In the Web site link given in the assignment description, you will see an interactive map of the world titled “GMD Measurement Locations.” You can zoom in and out and move the map around within the window. In the map, choose 5 sites that are labeled with a star, which will have CO
2
concentrations. Follow the steps below to fill in the data table:
1.
Click on a starred location. (One site will not have CO
2
concentrations.)
2.
Once the starred location opens, on the right side of the screen, click on the pictured graph “Examples of Data” for CO
2
.
3.
Once the graph opens, make a note of the CO
2
concentrations from previous years to present day. Fill in the table below.
4.
Repeat steps 1–3 for all other locations.
5.
Use these results in your lab report to help you assess CO
2
concentration trends from 1990 to 2005.
Location Code
Name of City/Country
CO
2
Emissions in 1990
CO
2
Emissions in 2005
Part II:
Write a 1-page lab report using the following scientific method sections:
•
Purpose
o
State the purpose of the lab.
•
Introduction
o
This is an investigation of what is currently known about the question being asked. Use background information from credible references to write a short summary about concepts in the lab. List and cite references in APA style.
•
Hypothesis/Predicted Outcome
o
A
hypothesis
is an educated guess. Based on what you have learned and written about in the Introduction, state what you expect to be the results of the lab procedures.
•
Methods
o
Summarize the procedures that you used in the lab. The Methods section should also state clearly how data (numbers) were collected during the lab; this will be reported in the Results/Outcome section.
•
Results/Outcome
o
Provide here any results or data that were generated while doing the lab procedure.
•
Discussion/Analysis
o
In this section, state clearly whether you obtained the expected results, and if the outcome was as expected.
o
Note: You can use the lab data to help you discuss the results and what you learned.
Provide references in APA format. This includes a reference list and in-text citations for references used in the Introduction section.
In this lab, you will gather data about CO
2
emissions using the National Oceanic and Atmospheric Administration Web site (Earth System Research Laboratory, n.d.) to help you write up a scientific report centered around known phenomena of CO
2
emissions, related to the following question:
Would you expe.
Environmental science
Science
Name:
Date:
Instructor’s Name:
Assignment:
Lab
Report
Title
:
Sources of CO
2
Emissions
Instructions:
You will need to write a 1-page lab report using the scientific method centered on the known phenomena of CO
2
emissions, related to the following question:
•
Would you expect to see an increase or decrease in CO
2
emission in the data over the past 40 years? Why?
When your lab report is complete, post it in Submitted Assignment files.
Part I:
In the Web site link given in the assignment description, you will see an interactive map of the world titled “GMD Measurement Locations.” You can zoom in and out and move the map around within the window. In the map, choose 5 sites that are labeled with a star, which will have CO
2
concentrations. Follow the steps below to fill in the data table:
1.
Click on a starred location. (One site will not have CO
2
concentrations.)
2.
Once the starred location opens, on the right side of the screen, click on the pictured graph “Examples of Data” for CO
2
.
3.
Once the graph opens, make a note of the CO
2
concentrations from previous years to present day. Fill in the table below.
4.
Repeat steps 1–3 for all other locations.
5.
Use these results in your lab report to help you assess CO
2
concentration trends from 1990 to 2005.
Location Code
Name of City/Country
CO
2
Emissions in 1990
CO
2
Emissions in 2005
Part II:
Write a 1-page lab report using the following scientific method sections:
•
Purpose
o
State the purpose of the lab.
•
Introduction
o
This is an investigation of what is currently known about the question being asked. Use background information from credible references to write a short summary about concepts in the lab. List and cite references in APA style.
•
Hypothesis/Predicted Outcome
o
A
hypothesis
is an educated guess. Based on what you have learned and written about in the Introduction, state what you expect to be the results of the lab procedures.
•
Methods
o
Summarize the procedures that you used in the lab. The Methods section should also state clearly how data (numbers) were collected during the lab; this will be reported in the Results/Outcome section.
•
Results/Outcome
o
Provide here any results or data that were generated while doing the lab procedure.
•
Discussion/Analysis
o
In this section, state clearly whether you obtained the expected results, and if the outcome was as expected.
o
Note: You can use the lab data to help you discuss the results and what you learned.
Provide references in APA format. This includes a reference list and in-text citations for references used in the Introduction section.
In this lab, you will gather data about CO
2
emissions using the National Oceanic and Atmospheric Administration Web site (Earth System Research Laboratory, n.d.) to help you write up a scientific report centered around known phenomena of CO
2
emissions, related to the following que.
Best Experimental Practices for Live Cell Imaging with the 3D Cell ExplorerMathieuFRECHIN
Nanolive’s 3D Cell Explorer allows for the creation of very powerful 3D images and 4D time-lapses
of living cells with very high spatio-temporal resolution (x,y:180nm; z:400nm; t:1.7sec). However, to
take full advantage of the microscope’s live imaging capabilities, a proper setup of Nanolive’s top
stage incubator is necessary. The goal is to guarantee maximal experimental stability and to avoid
any stress to the cells while they are in the top stage incubator.
In this application note we will describe how to properly set up Nanolive’s top stage incubator such
that mammalian cells can be imaged over a long period of time (up to weeks). To achieve this, we
will guide you through the key steps for optimal humidity, CO2 and temperature control as well as
correct imaging regime. You should then be able to take advantage of the most impressive and
unmatched 3D Cell Explorer capability: long-term, high-frequency live imaging.
The Scientific MethodHands-On Labs, Inc.Version 42-0313-00-.docxjoshua2345678
The Scientific Method
Hands-On Labs, Inc.
Version 42-0313-00-01
Lab Report Assistant
This document is not meant to be a substitute for a formal laboratory report. The Lab Report Assistant is simply a summary of the experiment’s questions, diagrams if needed, and data tables that should be addressed in a formal lab report. The intent is to facilitate students’ writing of lab reports by providing this information in an editable file which can be sent to an instructor.
Exercise 1: Investigating the Weight of Carbon Dioxide
Data Table 1. Investigation of the Weight of Carbon
Step 1: Make observations
Baking Soda
Vinegar
Reaction
Step 2: Ask a Question and Conduct Background Research
Question
Mass (amu) of CO2
44.01 amu
Mass (amu) of Air
28.82 amu
Notes about Gases
Step 3: Formulate a Hypothesis
Hypothesis
Step 4: Test the Hypothesis
Experimental Observations
Step 5: Analyze the Data and Draw Conclusions
Conclusions (If and Why Hypothesis was Supported or Rejected)
Questions
A. Why is a hypothesis supported or rejected, rather than being proven true or false?
B. Is an experiment considered to be a failure if the hypothesis is not supported? Explain your answer.
C. What gas did you find to be in the glass after mixing the baking soda and vinegar? Explain how you are certain.
D. Did you collect quantitative or qualitative data during this experiment? Explain your answer.
E. Describe your conclusions, including the observations that led to your conclusions.
Exercise 2: Modeling Global Warming
Data Table 2. Modeling Global Warming
Global Warming Synopsis
Sources
Data Table 3. Model #1 vs. Model #2
Model #1 vs. Model #2
Independent Variable
Dependent Variable
Control
Hypothesis
Data Table 4. Temperature and Greenhouse Gases
Time (minutes)
Model #1: Temperature (°C)
Model #2: Temperature (°C)
Notes
0
5
10
15
20
25
30
35
40
45
50
55
60
Change in Temperature:
Data Table 5. Global Warming Model Results
Model #1 vs. Model #2
Change in Temperature of Model #1 (°C)
Change in Temperature of Model #2 (°C)
Graph of Results
Conclusions (If and Why Hypothesis was Supported or Rejected)
Questions
A. Compare temperature measurements between the two models. Which model showed the greatest increase in temperature? Which model showed the least increase? Answer these questions by writing a short, descriptive paragraph comparing the models.
B. Describe the role of the plastic wrap in the experiment including both the similarities and dissimilarities to greenhouse gases.
C. If a third model (Model #3) was created by adding greenhouse gases, such as water vapor or carbon dioxide, and covered with plastic wrap and put into direct sunlight with Model #2, how would the temperatures vary? Explain your answer.
D. Relate the findings of this experiment to global warming. Include the benefits of greenhouse gases, but also describe the impact that excessive amounts of greenhouse gases have on global temperat.
CO2 Incubator is designed and manufactured using the accumulated expertise and knowledge that Esco has developed with over 35 years of world class equipment for laboratory usage. Designed with sample safety, energy efficiency and user-friendliness in mind, the system achieves precise parameter controls, highly effective contamination control and intuitive user interfaces all--supported by Esco's solution-based sales and service representatives worldwide.
1. DATA LOGGING
PHOTOSYNTHESIS,OXYGEN
AND CARBON DIOXIDE
Jusman Muktar
(D20101037504)
Nur Fatin Afiqah Kamaruzaman
( D20101037540)
Faiznur Ishak
( D20101037542)
2. WHAT IS DATA LOGGER ?
A data logger is a basic box capable of picking up and
storing signals from sensors. For ease of use they
generally have a minimum number of displays and
controls and their portability enables remote data
logging for example logging data away from the
computer.
Data loggers are either fitted with an internal battery
that is rechargeable or use regular alkaline
batteries. Some may also have external power
supplies. Most data loggers store data in non-
volatile memory, which means the data will not be
lost if the power supply fails.
3. It is important to note that low battery charge may
cause some data loggers to behave erratically. A
cable or docking station is normally provided to
facilitate a connection to a computer or other
hardware. Data loggers can also make use of
Bluetooth or Infra red communication to transfer
data.
4. ENGAGING
Plants make sugar, storing the energy of the sun
into chemical energy, by the process of
photosynthesis.
When they require energy, they can tap the stored
energy in sugar by a process called cellular
respiration.
5. The process of photosynthesis involves the use of
light energy to convert carbon dioxide and water
into sugar, oxygen, and other organic compounds.
This process is often summarized by the following
reaction:
6 H2O + 6 CO2 + light energy → C6H12O6 + 6 O2
6. Cellular respiration refers to the process of
converting the chemical energy of organic
molecules into a form immediately usable by
organisms. Glucose may be oxidized completely if
sufficient oxygen is available by the following
equation:
C6H12O6 + 6 O2 → 6 H2O + 6 CO2 + energy
7. PROBLEM STATEMENT
1. What gas will be released and consumed for
photosynthesis?
2. What is the type of gas sensor that need to be used for
this photosynthesis gas experiment?
3. How to set up and connect the gas sensor to the
computer correctly for this experiment?
4. What is the correct way/procedure to use the sensor in
order to measure the amount of gas that is released
and consumed by a plant during photosynthesis more
accurately.
8. 5. What is the precaution step that need to be taken while using
the sensor?
6. What is the correct and precise method to take the reading
from the sensor?
7. How to calculate the rate of respiration/photosynthesis from
the graph displayed on the monitor?
8. How the application of the gas sensor help you to obtain
result that is more accurate?
9. Can the use of the gas sensor help to reduce the difficulty of
the experiment?
10. Is the use of the sensor burden students and make things
complicated?
9. EMPOWERING
Objectives :
1. To measure the amount of oxygen gas consumed
or produced by plant during respiration and
photosynthesis
2. To measure the amount of carbon dioxide gas
consumed or produced by plant during respiration
and photosynthesis
3. To determine the rate of respiration and
photosynthesis of plant
10. PROCEDURE :
1. Plug the O2 Gas Sensor into
Channel 1 and the CO2 Gas
Sensor into Channel 2 of the
LabPro or CBL 2 interface.
Use the link cable to connect
the TI Graphing Calculator to
the interface. Firmly press in
the cable ends.
2. Turn on the calculator and
start the DATAMATE
program. Press CLEAR to
reset the program.
11. 3. Set up the calculator and interface for an
O2 Gas Sensor and CO2 Gas Sensor.
a) Select SETUP from the main screen.
b) If the calculator displays an O2 Gas
Sensor in CH 1 and a CO2 Gas Sensor in
CH2, proceed directly to Step 4. If it does
not, continue with this step to set up your
sensors manually.
c) Press ENTER to select CH 1.
d) Select OXYGEN GAS from the SELECT
SENSOR menu.
e) Select parts per thousand (PPT) as the
unit.
f) Press once, and then press ENTER to
select CH2.
g) Select CO2 GAS from the SELECT
SENSOR menu.
h) Select parts per thousand (PPT) as the
unit.
12. 4. Set up the data-collection mode.
a) To select MODE, press (the up
arrow key) twice and press
ENTER.
b) Select TIME GRAPH from the
SELECT MODE menu.
c) Select CHANGE TIME
SETTINGS from the TIME
GRAPH SETTINGS menu.
d) Enter “15” as the time between
samples in seconds.
e) Enter “40” as the number of
samples (data will be collected
for 10 minutes).
f) Select OK twice to return to the
main screen.
13. 5. Obtain several leaves
from the resource
table and blot them
dry, if damp, between
two pieces of paper
towel.
6. Place the leaves into
the respiration
chamber, using
forceps if necessary.
Wrap the respiration
chamber in aluminum
foil so that no light
reaches the leaves.
14. 7. Insert the CO2–O2 Tee into the
neck of the respiration chamber.
Place the O2 Gas Sensor into the
CO2–O2 Tee as shown in Figure
1. Insert the sensor snugly into
the Tee. The O2 Gas Sensor
should remain vertical throughout
the experiment. Place the CO2
Gas Sensor into the Tee directly
across from the respiration
chamber as shown in Figure 1.
Gently twist the stopper on the
shaft of the CO2 Gas Sensor into
the chamber opening. Does not
twist the shaft of the CO2 Gas
Sensor or you may damage it.
15. 8. Wait two minutes, and then
select START to begin data
collection. Data will be collected
for 10 minutes.
9. When data collection has
finished, remove the aluminum
foil from around the respiration
chamber.
10. Fill the tissue culture flask
with water and place it between
the lamp and the respiration
chamber. The flask will act as a
heat shield to protect the plant
leaves.
16. 11. Turn the lamp on. Place the lamp as
close to the leaves as reasonable. Do
not let the lamp touch the tissue
culture flask.
12. Press ENTER to view the graph of
O2 GAS VS. TIME. Sketch a copy of
your graph in the Graph section
below. When finished, press ENTER
to return to the graph menu. Press
once, and then press ENTER to view
the graph of CO2 GAS VS. TIME.
Sketch a copy of your graph in the
Graph section below. When finished,
press ENTER to return to the graph
menu. Select MAIN SCREEN from
the graph menu.
17. 13. Perform a linear regression to calculate the rate of
respiration/photosynthesis.
a) Select ANALYZE from the main screen.
b) Select CURVE FIT from the ANALYZE OPTIONS menu.
c) Select LINEAR (CH 1 VS TIME) from the CURVE FIT menu.
d) The linear-regression statistics for these two lists are displayed
for the equation in the form: Y=A∗X+B
e) Enter the value of the slope, A, as the rate of
respiration/photosynthesis in Table 1.
f) Press ENTER to view a graph of the data and the regression
line.
g) Press ENTER to return to the ANALYZE menu.
h) Repeat Steps 13b – 13g to calculate the
respiration/photosynthesis rate using the data from the CO2
Gas Sensor (CH 2 VS TIME).
i) Select RETURN TO MAIN SCREEN from the ANALYZE menu.
18. 14. Repeat Steps 8 – 13 to collect data with the plant
exposed to light.
15. Remove the plant leaves from the respiration
chamber, using forceps if necessary. Clean and dry
the respiration chamber.
19. RESULT :
Leaves O2 rate of CO2 rate of
production/consumpti production/consumpti
on (ppt/s) on (ppt/s)
In the dark - 0.0023 0.00065
In the light 0.0045 - 0.00126
21. DISCUSSION
1. Were either of the rate values for CO2 a positive
number? If so, what is the biological significance of
this?
The CO2 rate value for leaves in the dark was a
positive number. The biological significance of this is
that CO2 is produced during respiration. This causes
the concentration of CO2 to increase, as sugar is
oxidized and broken into CO2, water and energy.
22. 2. Were either of the rate values for O2 a negative number?
If so, what is the biological significance of this?
The O2 rate value for leaves in the dark was a
negative number. The biological significance of this is
that O2 is consumed during cellular respiration. This
causes the concentration of O2 to decrease as glucose
is oxidized for energy.
3. Do you have evidence that cellular respiration occurred
in leaves? Explain.
Yes, cellular respiration occurred in leaves since O2
decreased when leaves were in the dark and
photosynthesis was not possible.
23. 4. Do you have evidence that photosynthesis occurred in leaves?
Explain.
Yes, photosynthesis occurred in leaves since O2 increased
when leaves were exposed to the light.
5. List five factors that might influence the rate of oxygen
production or consumption in leaves. Explain how you think
each will affect the rate?
A greater number of leaves should increase the rate since
there are more chloroplasts to undergo photosynthesis and
more cells to require energy through cellular respiration.
A greater light intensity will increase the rate of
photosynthesis. It may not affect the rate of cellular
respiration.
24. A cooler room may decrease both rates, as cellular
metabolism decreases in cooler weather.
Facing the top of the leaves toward the light should
increase the rate of photosynthesis, since the
chloroplasts are closer to the light source.
If the plants overheat due to the heat from the lamp,
they may wilt and stop functioning. This will decrease
all rates.
If there too many leaves, diffusion may be restricted
and prevent accurate readings. This may apparently
decrease both rates.