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Photosynthesis Notes
All cells need energy to carry out their
functions, such as making proteins and
transporting substances into and out of
the cell
www.kidslu.com/science/mitoch
ondria.php
Plants use energy in sunlight to
make their own food
Photosynthesis – the process by which a
cell captures energy in sunlight and uses
it to make food
The Two Stages of Photosynthesis!
During photosynthesis, plants and some other
organisms use energy from the sun to convert carbon
dioxide and water into oxygen and sugars
http://www.emaki.net/blog/2007/03/photosynthesis.html
Stage 1: Capturing the Sun’s Energy
This process occurs mostly in the leaves – the green color comes from
the pigments, which are colored chemical compounds that absorb
light (chloroplasts are the green organelle inside plant cells)
The main photosynthetic pigment in chloroplasts (the site for
photosynthesis) is chlorophyll!
Stage 2: Using Energy
to Make Food
Next, the cell uses the
captured energy to
produce sugars - the cell
needs two raw materials
for food to be made –
Water (H2O) &
Carbon Dioxide (CO2)
1. The root absorbs water from the soil
2. Then the water moves up through the plant’s stem to the leaves
3. Carbon Dioxide enters the plant through the small openings on
the underside of the leaves called the stomata
4. Once in the leaves, the water and carbon dioxide move into the
chloroplasts
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garden.com/thepla
nt.html
Inside the chloroplasts, the H2O and CO2 undergo a complex
series of chemical reactions.
H2O + CO2 →
……………….
…… →
O2 + C6H12O6
Oxygen (O2) and Six-carbon sugars (C6H12O6) are produced!
Almost ALL of the oxygen in the Earth’s air was produced
by living things through the process of photosynthesis!
Chemical Equation for
Photosynthesis
Light Energy
6 CO2
+
Carbon Dioxide
Reactants
6 H2O → C6H12O6 +
Water
Sugar
6 O2
Oxyg
Products
A look at things to come…….