Download Joseph Geissler

Joseph Geissler
Newark Science Park High School
Mrs. Paulose
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Structure of leaf
Structure of a chloroplast
Importance of photosynthesis
General equation of photosynthesis
Light vs dark reactions
Definitions of ATP, NADP+, ATP synthase,
electron transportation
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Humans are heterotrops
◦ Animals, fungi and many bacteria
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Are there any organism that are able to make
their own food?
Autotrophs
◦ Plants, algae, and many bacteria
Thylakoid Membrane
Stroma
Intermembrane Space
Cristae
Matrix
Stroma
•Interior space of the chloroplasts
•Contains metabolic enzymes, as well a
special set of ribosomes, RNA and DNA
Thylakoid Membrane
•Network of flattened disclike sacs
(thylakoids) which create a third
internal compartment separate from
the stroma
•The site of the light-capturing
systems, the electron-transport chains,
and ATP synthase
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The process by which green plants make their
own food using carbon dioxide and water in
the presence of sun light.
6CO2 + 6 H2O + light energy
C6H12O6 + 6O2
Objective:
Investigate the rate of O2 production and CO2 consumption in an
aquatic plant
Methods:
1)
2)
3)
4)
Open LoggerPro exercise 31C in Vernier for Biology
Attach gas probe to computer (probe interface will load)
Place probe in beaker containing water and aquatic plant life
For the first part of the exercise, cover the biochamber, restricting
its exposure to light
--Using LoggerPro, collect data for 15 minutes
5) Next, collect 2.5 minutes of data while plant is covered. Then.
remove the cover and continue collection for an additional 2.5
minutes (for a total of 5 minutes)
6) Finally, place the plant in front of lamp
--Using LoggerPro, collect data for 5 minutes
Results:
-- Determine the slope of the line generated in LoggerPro for
each situation
Conclusions:
--How does the amount of oxygen in the aquatic
environment compare among the thee recordings?
How do the slopes compare?
If different, by how much? Why do you think these values
differ?
--How does sunlight drive photosynthesis? Can
photosynthesis occur without sunlight?
--Describe the similarities and differences between
mitochondria and chloroplasts.
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Light absorbing pigment that plays a central role
in photosynthesis
Long hydrophobic tails (in yellow) anchor
chlorophyll to the thylakoid membrane
Light is absorbed by electrons within the bond
network (in blue)
Chlorophyll are arranged in and around
photosystems embedded in the thylakoid
membrane
Electrons in chlorophyll molecules interact with
photons from light are raised to a higher energy
level
A.
B.
(A) Charge separation
generated in pigmentprotein complex of a
chlorophyll molecule to drive
(B) the donation of a highenergy electron to the
electron-transport chain
Student photosystems demonstration
Photosystem II
--Produces high-energy
electrons to be propelled
along the electron-transport
chain
--Electron transportation
drives H+ pump creating a
proton gradient
--ATP synthase uses this
gradient to drive ATP
synthesis (video)
Photosystem I
--Finally, the highenergy electron arrives at
photosystem I
--Here, it will fill a
positively charged ‘hole’
which has been left in the
reaction center of
chlorophyll
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Light reactions (photosynthetic electron-transfer
reactions) Photosystems
◦ Energy from sun light excites electrons within
chlorophyll, enabling electrons to move along an
electron transport chain in the thylakoid membrane
 Electrons are obtained from the splitting of water molecules,
which produces O2 as a byproduct
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Dark reactions (carbon-fixation reactions) Calvin
Cycle
◦ ATP and NADPH generated from light reactions serve as
a source of energy and reducing power, respectively, to
drive the conversion of CO2 to carbohydrate, such as
sucrose
 These organic molecules can then be exported to other
tissues as a source of energy
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Properly functioning chloroplasts
Properly functioning chlorophyll molecules
Well established electron transport chain
Optimum exposure to sun light
Steady supply of water and nutrients
Steady removal of waste by products
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Environmental conditions can strongly affect
photosynthesis
Light intensity
Temperature
Concentrations of CO2
Concentrations of O2
Foreign substances in soil
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Which of the following is the correct formula
which describes photosynthesis?
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A) O2 + H2O + light
B) C6H12O6 + light
C) CO2 + O2 + light
D) CO2 + H2O + light
C6H12O6 + CO2
CO2 + H2O
C6H12O6 + O2
C6H12O6 + O2 + H2O
Balance the equation of your answer
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Which organelle in plants is the site for
photosynthesis?
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A) Stroma
B) Chlorophyll
C) Chloroplast
D) Mitochondria
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What gas occupies the intercellular space of
the mesoderm on a bright sunny day?
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A) Nitrogen
B) Carbon Dioxide
C) Hydrogen
D) Oxygen
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Which of the following events takes place
during light reactions?
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A) Combination of H and CO2
B) Combination of C and CO2
C) Splitting of H2O
D) Splitting of CO2
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Which of the following events takes place
during dark reactions?
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A) Combination of H and CO2
B) Combination of C and CO2
C) Splitting of H2O
D) Splitting of CO2
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From where does the low-energy electron
responsible for releasing the high-energy
electron come from?
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A) CO2
B) NADPH
C) ATP
D) H2O
E) None of the above
Molecular Biology of the Cell, Reference Edition
Bruce Alberts, Alexander Johnson, Julian
Lewis, Martin Raff, Keith Roberts, and
Peter Walter. New York: Garland Science;
2002.