Transcript Section 8-2 - local.brookings.k12.sd.us

Interest Grabber
Section 8-2
Trapping Energy
Have you ever used a solar-powered
calculator? No matter where you go,
as long as you have a light source,
the calculator works. You never have
to put batteries in it.
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Interest Grabber continued
Section 8-2
1. A solar-powered calculator uses solar cells that are
found in rows along the top of the calculator. Into
what kind of energy is the light energy converted so
that the calculator works?
2. Recall that plants use light energy from the sun to
make food. Into what kind of energy is the light
energy converted by plants?
3. Most plants, no matter what size or shape they are,
have some parts that are green. Which parts of a
plant are usually green?
4. What does the green color have to do with the plant’s
ability to convert light energy into the energy found in
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the food it makes?
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Interest Grabber Answers
Section 8-2
1. A solar-powered calculator uses
solar cells that are found in rows
along the top of the calculator. Into
what kind of energy is the light
energy converted so that the
calculator works?
They convert light energy into
electrical energy.
Interest Grabber Answers
Section 8-2
2. Recall that plants use light energy
from the sun to make food. Into what
kind of energy is the light energy
converted by plants?
Plants convert light energy into
chemical energy.
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Interest Grabber Answers
Section 8-2
3. Most plants, no matter what size
or shape they are, have some parts
that are green. Which parts of a plant
are usually green?
Leaves are green, as are some
stems.
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Interest Grabber Answers
Section 8-2
4. What does the green color have to do with the
plant’s ability to convert light energy into the
energy found in the food it makes?
The green color is the pigment chlorophyll,
which absorbs light energy
from the sun and converts it to chemical energy
in the process
of photosynthesis.
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Section Outline
Section 8-2
8–2 Photosynthesis: An Overview
A.Investigating Photosynthesis
1. Van Helmont’s Experiment
2. Priestley’s Experiment
3. Jan Ingenhousz
B.The Photosynthesis Equation
C.
Light Pigments
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Research into PHOTOSYNTHESIS
began centuries ago with this
simple question:
When a tiny seed grows into a
huge plant, where does all the
“new plant” come from?
http://www.nofretete-page.de/gemischtNeu/TN_plant_grow_w.JPG
EXPERIMENTS TO FIND OUT
In 1643a Belgian physician Jan van Helmont
determined the mass of a pot of dry soil
and a small seedling.
Then he planted the seedling in the pot and watered
it regularly.
At the end of 5 years the seedling had gained about
75 kg, but the mass of the soil was almost
unchanged.
The “increase in plant” had to come from
the water… that was the only thing he had added!
http://www2.nsta.org/Energy/find/primer/primer2_3.html
EXPERIMENTS TO FIND OUT
1771- An English minister,
Joseph Priestley, discovered
that a flame burning in a closed
jar would die out.
http://www2.nsta.org/Energy/find/primer/primer2_7.html
http://www2.nsta.org/Energy/find/primer/primer2_8.html
If he placed a live plant in the jar
and allowed a few days to pass,
the candle could be lit again.
The plant produced something
“required for burning” that the candle used up
OXYGEN
We now know it was …____________
EXPERIMENTS TO FIND OUT
1779Dutch scientist Jan Ingenhousz
showed Priestley’s plant experiment only worked
if the plant was exposed to light !
http://www.rgg.og.schule-bw.de/Dokus/d-faech/Biologie/Klasse%208/Bilder/Fotosynthese/Ingenhousz-Netz.JPG
Photosynthesis
______________ involves a
complex series of chemical
reactions, in which the
product of one reaction is
consumed
in the next reaction.
_________________________
By: VanderWal
A series of reactions linked in this
way is referred to as a
biochemical pathway.
_________________________
Video 2
Photosynthesis
Click the image to play the video segment.
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THE BIG PICTURE
These experiments led to work by later
scientists who finally discovered that in the
presence of light, plants transform CO2 and water
into carbohydrates and release oxygen.
Carbon
WATER
_____________
+
____________
dioxide
6 CO2 + ____________
6 H 2O
_____________
Sugars
Oxygen
_______________ + ____________
→
C6H12O6 + ____________
6 O2
_______________
Photosynthesis: Reactants and Products
Section 8-2
Light Energy
Chloroplast
CO2 + H2O
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Sugars + O2
PHOTOSYNTHESIS
Light &
Water
Light-Dependent
Reaction
Water &
oxygen
ATP
NADPH
Carbon
Dioxide
Light-Independent
Reactions
(CH2O)n
PHOTOSYNTHESIS
Light &
Water
Light-Dependent
Reaction
Water &
oxygen
ATP
NADPH
Carbon
Dioxide
Carbon Fixation
(Calvin Cycle)
sugars
WE NEED CARRIERS
Molecule that carries
ATP
= _______
Molecule that carries
HIGH ENERGY ELECTRONS
+
NADP
= ___________
Myth:
Many people think that plants
are green because they use green
light in photosynthesis.
_________________________
Plants appear green because
they contain large amounts of
chlorophyll which
reflects (or transmits) green
wavelengths
of light.
_________________________
By: VanderWal
Plants absorb and use mainly
red and blue wavelengths of light
_______________
for photosynthesis.
By: VanderWal
When you see a plant with
yellow flowers and green leaves,
the plant is
reflecting yellow
and green
wavelengths of light.
______________
By: VanderWal
When you see a plant with
yellow and purple flowers, the
plant is
reflecting yellow
and purple
wavelengths
of light.
______________
By: VanderWal
Sunlight is made up
of many different
wavelengths of
light
Your eyes “see”
different
wavelengths as
different colors
http://www.simontucket.com/_Portfolio/PortLarge/L_Il_Prism.jpg
Sizes of Wavelengths
http://www.ology.amnh.org/einstein/lightmatterenergy/light.html
CHLOROPHYLL is the main energy
pigment
absorbing molecule (=_____________)
used by green plants to absorb sunlight.
There are two types of chlorophyll
Chlorophyll a
Chlorophyll b
________________
& _________________
We “see” reflected light
Chlorophyll absorbs other wavelengths
and reflects green wavelengths to your
eyes so leaves “LOOK” green
Image modified from: http://www.visibledreams.net/Web/color/color_3.html
Absorption of Light by
Chlorophyll a and Chlorophyll b
© Pearson Education, Inc. Publishing as
Pearson Prentice-Hall. All rights reserved.
Chlorophyll b
Chlorophyll a
Chlorophyll a absorbs less
blue light but more red light.
________________________
Absorption of Light by
Chlorophyll a and Chlorophyll b
© Pearson Education, Inc. Publishing as
Pearson Prentice-Hall. All rights reserved.
Chlorophyll b
Chlorophyll a
Chlorophyll a and chlorophyll b __________
do not
__________________
absorb green light.
Why are plants green?
http://www.mhhe.com/biosci/pae/botany/uno/graphics/uno01pob/vrl/images/0160.gif
Chlorophyll absorbs
light very well in the
blue-violet and red
regions and NOT
well in the green
regions of spectrum.
Chlorophyll a and chlorophyll b
allow green light to
be
reflected.
___________
By: VanderWal
Plant’s gather the sun’s energy
with light absorbing molecules
pigments
called ___________.
By: VanderWal
The plant’s
principal
pigment is
chlorophyll
________________.
By: VanderWal
Carotenoids (yellow, orange, and brown
pigments) are pigments too.
Figure 8-5 Chlorophyll Light Absorption
Section 8-2
Absorption of Light by
Chlorophyll a and Chlorophyll b
Chlorophyll b
Chlorophyll a
V
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B
G
YO
R
BIOLOGY; MIller and Levine; Prentice Hall; 2006
When
chlorophyll
absorbs
light energy,
much of the
energy is transferred directly to
electrons in the chlorophyll
molecule.
ENERGY & ELECTRONS
http://www.mhhe.com/biosci/pae/botany/uno/graphics/uno01pob/vrl/images/0160.gif
When chlorophyll
absorbs light, the
energy is transferred
to electrons in the
chlorophyll molecule.
ELECTRONS
HIGH ENERGY ____________
make photosynthesis work!
http://www.wjcc.k12.va.us/ROBB/Atom%20Animation%20Resources_files/image003.gif
SOUTH DAKOTA SCIENCE
STANDARDS
Chapter 8 - Photosynthesis:
The students will be able to:
• explain the biochemical processes that a plant
uses in photosynthesis
• explain the role ADP-ATP cycle has within the
chloroplast of the cell (9-12.L.1.1)
• explain the light reaction (9-12.L.1.1)
• explain the steps of photophosphorylation and
the Calvin Cycle (9-12.L.1.1)
SOUTH DAKOTA
CORE SCIENCE STANDARDS
LIFE SCIENCE:
Indicator 1: Understand the fundamental structures,
functions, classifications, and mechanisms found
in living things
9-12.L.1.1. Students are able to relate cellular
functions and processes to specialized
structures within cells.
• Photosynthesis and respiration
ATP-ADP energy cycle
Role of enzymes
Mitochondria
Chloroplasts
Core High School Life Science
Performance Descriptors
High school students
performing at the
ADVANCED level:
explain the steps of photophosphorylation and the
Calvin Cycle;
analyze chemical reaction and chemical processes
involved in the Calvin Cycle and Krebs Cycle;
predict the function of a given structure;
High school students
performing at the
PROFICIENT level:
describe and give examples of chemical reactions
required to sustain life (…role of enzymes)
describe and give examples of chemical reactions
required to sustain life (hydrolysis, dehydration
synthesis, photosynthesis, cellular respiration, ADP/ATP,
role of enzymes);
describe the relationship between structure and function
High school students
performing at the
BASIC level
name chemical reactions required to sustain life
(… role of enzymes)
name chemical reactions required to sustain life
(hydrolysis, dehydration synthesis, photosynthesis,
cellular respiration, ADP/ATP, role of enzymes);
recognize that different structures perform different
functions;
SOUTH DAKOTA ADVANCED SCIENCE
STANDARDS
LIFE SCIENCE:
Indicator 1: Understand the fundamental structures,
functions, classifications, and mechanisms found
in living things.
9-12.L.1.1A. Students are able to explain the physical and
chemical processes of photosynthesis and cell
respiration and their importance to plant and animal life.
(SYNTHESIS)
Examples:
photosystems, photophosphorylation, Calvin Cycle and
Krebs Cycle