Download Photosynthesis - ABC-MissAngelochsBiologyClass

PHOTOSYNTHESIS
WHAT IS PHOTOSYNTHESIS??
• Photosynthesis is
the process where
light energy (Sun) is
converted to
chemical energy in
the form of organic
molecules (sugar)
• The process
autotrophs use to
make their own
food. (Glucose)
6CO2 + 6H2O  C6H12O6 + 6O2
Question:
Where does
photosynthesis
take place?
3
Plants
• Mainly occurs in the leaves:
stoma – pores found
on the bottom of leaves
Stoma
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Stomata (stoma)
Pores in a plant’s cuticle (skin)
where water vapor and gases (CO2
& O2) are exchanged between the
plant and the outside environment.
Stoma
Carbon Dioxide
(CO2)
Guard Cell
Oxygen
(O2)
Guard Cell
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Chloroplast
Organelle where photosynthesis
takes place.
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Question:
Why are
plants
green?
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• The different wavelengths are
either absorbed or reflected.
• The ‘color’ we see is the
wavelength(s) that are reflected
(ie: not absorbed)
• Sunlight (white light) is made up
of all the colors in the visible
spectrum. (*** borrow
spectroscope)
• What makes something appear
black?
So…. Why are plants green?
• Plants are green because the
green wavelength is reflected, not
absorbed.
Chlorophyll
• Plants get the sun’s energy with light
with light absorbing molecules called
pigments.
Absorption
violet
blue
green
yellow
wavelength
orange
red
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Chlorophyll
• Chlorophyll is the main pigment
in plants.
• 2 Types
– Chlorophyll A: Absorbs violet and
red
– Chlorophyll B: Absorbs blue and red
Wavelength of Light (nm)
400
500
600
700
Short wave
Long wave
(more energy)
(less energy)
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Question:
During the fall,
what causes the
leaves to change
colors?
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Fall Colors
• In addition to the chlorophyll
pigments, there are other pigments
present.
• During the fall, the green
chlorophyll pigments are greatly
reduced revealing the other pigments
• Why do you think this is?
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Accessory Pigments
• Carotenoids (or carotene) pigments
are red, orange, or yellow
pigments
• Xanthophyll – yellow pigments
Question:
What do
cells use
for energy?
17
Energy for Life on Earth
• Sunlight is the ULTIMATE
energy for all life on Earth
• Plants store energy in the
bonds of sugars
• Chemical energy is released as
ATP during cellular respiration
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