Transcript Photosynthesis

Photosynthesis
Organisms make food using
light energy
many kinds of organisms carry out
photosynthesis
Multicellular plants
bacteria
Blue-green algae
Plants provide food
for animals, and us, too
Photosynthesis
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Needs co2 & h2o
Needs light energy
Makes sugar
Makes o2
leaf
Photosynthesis equation
6CO2 + 6H2O
C6H12O6 + 6O2
Complex carbohydrates,
proteins, fats, amino acids,
enzymes, coenzymes, pigments
Light Energy – The
the part we can see and the plants
use!
PLANT PIGMENTS ABSORB CERTAIN
WAVELENGTHS OF THE VISIBLE
SPECTRUM (SUNLIGHT)
Chlorophyll b
Chlorophyll a
Beta-carotene
phycoerythrin
phycocyanin
Plants are green because they reflect
the green wavelengths and absorb
(and use) the others.
• Your favorite blue shirt is blue because it
reflects blue wavelengths and absorbs the
other wavelengths ….
• Plants reflect green wavelengths.
Chlorophylls – the major
energy absorbers
Accessory pigments help
absorb energy – they
send what they absorb
to chlorophyll a
The leaf is the primary
photosynthetic organ of the plant
Leaves take in CO2 while
roots take in H2O
Chloroplasts are found in the cells of
the leaf and other photosynthetic
parts of the plant
Green plant cells
contain chloroplasts
Leaf Cross section
This is what happens in
photosynthesis
Light reactions
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Calvin cycle
Two steps of photosynthesis
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2
Light Reactions
air
Calvin cycle
Light reactions
Photosynthesis occurs as long as light is available
Photosynthesis occurs all day
Photosynthesis and
respiration are
interdependent upon
each other – plants carry
out both processes
goodnight