Download Where does photosynthesis take place?

Question:
Where does
photosynthesis
take place?
1
Plants
• Autotrophs – produce their own food
(glucose)
• Process called photosynthesis
• Mainly occurs in the leaves:
a. stoma - pores
b.mesophyll cells
Mesophyll
Cell
Chloroplast
Stoma
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Stomata (stoma)
Pores in a plant’s cuticle through
which water vapor and gases (CO2
& O2) are exchanged between the
plant and the atmosphere.
Stoma
Carbon Dioxide
(CO2)
Guard Cell
Oxygen
(O2)
Guard Cell
Found on the underside of leaves
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Mesophyll Cell of Leaf
Nucleus
Cell Wall
Chloroplast
Central Vacuole
Photosynthesis occurs in these cells!
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Chloroplast
Organelle where photosynthesis
takes place.
Stroma
Outer Membrane
Inner Membrane
Thylakoid
Granum
Thylakoid stacks are connected together
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Thylakoid
Thylakoid Membrane
Granum
Thylakoid Space
Grana make up the inner membrane
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Question:
Why are
plants
green?
7
Chlorophyll Molecules
• Located in the thylakoid membranes
• Chlorophyll have Mg+ in the center
• Chlorophyll pigments harvest energy
(photons) by absorbing certain
wavelengths (blue-420 nm and red660 nm are most important)
• Plants are green because the green
wavelength is reflected, not absorbed.
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Wavelength of Light (nm)
400
500
600
700
Short wave
Long wave
(more energy)
(less energy)
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Absorption of Light by
Chlorophyll
Chlorophyll absorbs blue-violet & red light best
Absorption
violet
blue
green yellow
wavelength
orange
red
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Question:
During the fall,
what causes the
leaves to change
colors?
12
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
• Carotenoids are pigments that are
either red, orange, or yellow
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Chloroplast
Outer Membrane
Inner Membrane
STROMA– where Calvin Cycle occurs
Thylakoid
Granum
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