Photosynthesis
What is photosynthesis?
• Photosynthesis may look like a large,
intimidating word. Let’s break it down in order
to get a general idea of what it means:
• "Photo" means light.
Synthesis means to put together
• During photosynthesis, plants use the energy
contained in this sunlight to turn carbon dioxide
and water into energy in the form of a
carbohydrate (sugar) called glucose.
electromagnetic energy becomes ________
chemical
So _____________
energy.
Photosynthesis
1. Radiant Energy from the sun is turned
into chemical energy.
2. The chemical energy is used to “put
together” glucose from carbon dioxide
“building blocks”
Photosynthesis Equation
6 CO2 + 12 H2O + Energy from Sunlight 
C6H12O6 + 6 O2 + 6 H2O
http://www.xtec.cat/~mherna23/summer03/amspot/picture/photosynthesis.jpg
6 molecules of carbon
dioxide combine with
12 molecules of water
in the presence of
sunlight energy to form
one molecule of sugar
plus 6 molecules of
oxygen and 6
molecules of water.
Where does photosynthesis
take place?
http://upload.wikimedia.org/wikipedia/commons/thumb/9/90/Leaf_anatomy.svg/769px-Leaf_anatomy.svg.png
Roots
“The Warehouse”
The three major functions of roots are
1. Absorption of water and inorganic
nutrients
2. Anchoring the plant body to the ground
3. Storage of foods
http://www.livingwilderness.com/southwest/pine-root-rock.jpg
Transport Tissues
“The Conveyor Belts”
• Xylem
– Transports water from the root to the plant
• Phloem
– Transports organic nutrients from the plant to
the root
http://upload.wikimedia.org/wikipedia/commons/thumb/9/90/Leaf_anatomy.svg/769pxLeaf_anatomy.svg.png
Epidermis
“The Outer Wall’
• The epidermis is the outer single-layered group
of cells covering a plant.
• The epidermis forms the boundary between the
plant and the external world. The epidermis
serves several functions: protection against
water loss, regulation of gas exchange, and
absorption of water and mineral nutrients.
http://upload.wikimedia.org/wikipedia/commons/thumb/9/90/Leaf_anatomy.svg/769px-Leaf_anatomy.svg.png
Palisade Cells
“The Assembly Lines”
• Palisade cells are a type of leaf tissues that
contain chloroplasts.
• Palisade cells are placed all over the top of a
leaf, maximizing the extent of light absorption.
As a result, the top of a leaf is often darker than
the bottom.
http://upload.wikimedia.org/wikipedia/commons/thumb/9/90/Leaf_anatomy.svg/769px-Leaf_anatomy.svg.png
Chloroplasts
“The Workers”
Leaves of plants have
chloroplasts that are filled
with chlorophyll, which
capture the energy from
the sunlight).
Water and carbon dioxide
move to the chloroplasts
and chemical reactions
there produce oxygen and
sugars.
http://micro.magnet.fsu.edu/cells/chloroplasts/images/chloroplastsfigure1.jpg
Chloroplasts Continued
“The Workers”
Cells can contain 50 or
more chloroplasts!
The thylakoids look like
coins. These contain
chlorophyll and are
responsible for collecting
light.
In the stoma, enzymes
assemble sugar
fragments from the CO2
and H2O.
http://micro.magnet.fsu.edu/cells/chloroplasts/images/chloroplastsfigure1.jpg
Stoma
“The Smoke Stack”
• The stoma is the opening that connects
the outside to the inside. Air flows into the
leaf through the stoma.
• The air brings carbon dioxide (CO2),
needed for photosynthesis, with it. Oxygen
(O2), a byproduct of photosynthesis, flows
out through the stoma.
http://upload.wikimedia.org/wikipedia/commons/thumb/9/9
0/Leaf_anatomy.svg/769px-Leaf_anatomy.svg.png
Virtual Lab
http://i.treehugger.com/images/2007/10/24/Stomata.jpg
http://i.treehugger.com/images/2007/10/24/chloroplast-jj-001.jpg
http://www.vcbio.science.ru.nl/images/fesem_epidermis_zoom_zlabel.jpg