CELLULAR ENERGY
PART I
PHOTOSYNTHESIS
PHOTOSYNTHESIS
[PHOTOSYNTHESIS] 6 CO2 + 6 H2O
 C6H12O6 + 6 O2
Carbon Dioxide + Water makes Glucose Sugar & Oxygen
(What goes in!)
(What is made!)
Plants make their own food (sugar) by combining carbon dioxide gas
and water.
PHOTOSYNTHESIS means “to make with light” in Root Words.
That is because plants need light energy to combine the water and
carbon dioxide.
HOW PLANTS GET THEIR
MATERIALS TO MAKE SUGAR
Sunlight hits the leaves and a
green pigment called
CHLOROPHYLL traps the
light’s energy.
HOW PLANTS GET THEIR
MATERIALS TO MAKE SUGAR
Roots pull water up
from the soil.
HOW PLANTS GET THEIR
MATERIALS TO MAKE SUGAR
CO2
CO2
CO2
CO2
Carbon Dioxide gas enters by
diffusion through openings in the
leaves called STOMATA.
HOW PLANTS GET THEIR
MATERIALS TO MAKE SUGAR
Sunlight hits the leaves and a green
pigment called CHLOROPHYLL
traps the light’s energy.
CO2
Carbon Dioxide gas enters by diffusion through
openings in the leaves called STOMATA.
Roots pull water up from the soil.
PLANT PIGMENTS
 Plants can have many different kinds of
pigments, or colored chemical compounds.
 The Most Important is CHLOROPHYLL:
the GREEN pigment used by plants to
capture light energy.
 Other pigments can include
Orange carotene (like “carrot”)
and Yellow xanthophyll.
CHLOROPHYLL
Chlorophyll is found inside the
CHLOROPLAST, a membrane bound
organelle.
Chlorophyll’s job is to trap the light energy
from the sun.
CHLOROPLAST
CHLOROPLAST
Let’s Look Inside!
CHLOROPLAST
CHLOROPLAST
Inside of Chloroplast
CHLOROPLAST
CHLOROPLAST
STROMA: a gelatinous material
CHLOROPLAST
THYLAKOID MEMBRANES stacked together
to form GRANA
LIGHT REACTION
O2
GRANA capture the sunlight energy.
H+
O2
H+
H+
This energy is used to split water molecules.
This is called HYDROLYSIS.
The Hydrogen moves into the STROMA,
and the Oxygen is released as a gaseous waste.
O2
LIGHT REACTION
O2
O2
H+
O2
H+
H+
This is called the LIGHT REACTION because it cannot happen
without light.
DARK REACTION
The reactions that occur in the STROMA do not require light.
Hydrogen from the Grana and CO2 from the air are chemically
bonded in a series of reactions
called the Calvin Cycle or DARK REACTIONS.
GLUCOSE Sugar is the end product and the whole purpose of
PHOTOSYNTHESIS.
DARK REACTION
CO2
CO2
H+
CO2
H+
Hydrogen from the Grana and CO2 from the air are chemically
bonded in a series of reactions
called the Calvin Cycle or DARK REACTIONS.
GLUCOSE Sugar is the end product and the whole purpose of
PHOTOSYNTHESIS.
DARK REACTION
H+
CO2
CO2
H+
Hydrogen from the Grana and CO2 from the air are chemically
bonded in a series of reactions
called the Calvin Cycle or DARK REACTIONS.
GLUCOSE Sugar is the end product and the whole purpose of
PHOTOSYNTHESIS.
GLUCOSE PRODUCTION
C6H12O6
C6H12O6
The final step is to move Glucose out of the Chloroplast and into
the plant cells for use as FOOD for energy.
REVIEW PHOTOSYNTHESIS
CO2 + H2O
 C6H12O6 + O2
The light reaction takes place in the GRANA STACKS.
The light energy is used to split water, or HYDROLYSIS.
The Hydrogen moves out to the STROMA.
The Oxygen gas leaves the plant as a waste product.
REVIEW PHOTOSYNTHESIS
CO2 + H2O
 C6H12O6 + O2
The Dark Reaction takes place in the STROMA.
Hydrogen from the Light Reaction is combined with
Carbon Dioxide gas from outside the leaf.
After a series of chemical reactions, GLUCOSE is
made and released from the Chloroplast for plant use.
WHAT DO PLANTS DO
WITH GLUCOSE?
Light from the sun takes 8 minutes to reach a plant on Earth.
Photosynthesis is rapid, and glucose can be produced almost
instantly after sunlight has hit a leaf.
Once Glucose is made, a plant can use the energy stored
in glucose to do many things. . . .
MAKE NEW CELLS
MAKE FLOWERS
REPRODUCE MORE PLANTS
GROW BIGGER
GROW LONGER ROOTS
MAKE THORNS TO PROTECT ITSELF
THE END OF PART I
STAY TUNED FOR PART II
GLUCOSE, WHAT IS IT GOOD
FOR?