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Photosynthesis
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Photosynthesis: the process by which a cell captures
energy in sunlight and uses it to make food
o Photo– means “light”, synthesis– means “putting together”
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Nearly all living things obtain energy either directly or
indirectly from the energy of sunlight captured during
photosynthesis
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Autotroph
o an organism that makes their own food
o What are some examples?
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Heterotroph
o an organism that cannot make their own food
o What are some examples?
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Fungi– absorb their food from other organisms
1.
Capturing the sun’s energy
2.
Producing sugars
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Both stages must occur in the correct order
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Energy capturing process occurs mostly in leaves
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The green color comes from pigments– colored chemical
compounds that absorb light
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The MAIN photosynthetic pigment in chloroplasts is called
CHLOROPHYLL
Chlorophyll captures light energy and
uses it to power the second stage
of photosynthesis…
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Cell uses captured energy to produce sugars
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The cell needs two raw materials
1.
2.
water – enters plant through roots and move upward to the leaf
carbon dioxide– enters through openings called stomata
Once in the leaves the water and
carbon dioxide move into the
chloroplasts….
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Inside the chloroplasts undergo a series of chemical
reactions
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Chemicals are the products of the reactions (2)
o Six-carbon sugar (use this energy to carry out cell functions)
o Oxygen (exits leaf through stomata)
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Fun Fact: Almost all oxygen in Earth’s atmosphere was
produced by living things through the
process of photosynthesis
Raw Materials
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The arrow stands for YIELDS
Products
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Plants use it for food
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Some sugar is made into other compounds, such as
cellulose
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Some sugar is stored in the plant’s cells for later use