1.
True or False – energy moves through a cycle (it is
recycled through the environment)
2. What do plants do with sunlight and what is “life’s
3.
4.
5.
6.
7.
8.
universal food”?
What group of organisms directly consume plant
sugar?
What group of organisms use the “leftover” biomass
for energy?
Define metabolism.
Why can there never be more lions than gazelles?
Give three reasons we are indebted to plants.
What molecules are cycled in a living system?
9. What two organelles does all life rely on for energy?
10. What processes take place within these organelles?
11. List the sequence of the real flow of energy through a
system.
12. Sugar is important for two reasons. What are they?
What
molecules go
in?
What form of
energy goes
in?
Organelle
What form of
energy comes
out?
What
molecules
come out?
I.
Plants and some other types of organisms are
able to use light energy from the sun to produce
food.
A. Autotrophs – organisms such as plants which
make their own food.
II. Some organisms cannot use the sun to produce
food.
B.
Heterotrophs – obtain energy from the foods
they consume.
III. Energy comes in many forms such as light, heat,
and electricity.
IV. Energy can be stored as chemical compounds.
V. One of the principle chemical compounds that
cells use to store and release energy is:
 Adenosine triphosphate (ATP)
 Basic energy source of all cells
 Storing energy
 Adenosine diphosphate (ADP)
 Releasing energy
 Adenosine triphosphate (ATP)
 When a tiny seedling grows into a tall tree
with a mass of several tons, where does the
tree’s increase in mass come from? From the
soil? From the water? From the air?
I.
Van Helmont’s Experiment
 Devised an experiment to find
out if plants grew by taking
material out of the soil.
 Step 1
 Determined the mass of a pot
of dry soil and a small willow
seedling
 Step 2

Planted the willow seedling
in the pot of soil
 Step 3
 Water it
regularly
 Step 5
 At the end of five
years Van Helmont
weighed the tree and
the soil
 Results
 Seedling gained about 75 kg
(~169 pounds)
 Mass of the soil was almost
unchanged (weighed 2
ounces less)
 Conclusions
 Most of the gain of mass had come
What
could
he conclude
from the
water because
that is the
only
thing
he added
with
what
he knew?
 Summarize Van Helmont’s experiment in
approximately 3-5 sentences. Make sure you
include his conclusions!
 Priestley’s Experiment
 Step 1

Took a candle and placed a glass jar over it,
and watched the flame gradually die out
 Conclusion
 Something in the air was necessary to keep
the candle flame burning.
OXYGEN
 Step 2
 Priestley placed a live sprig of mint under the
jar.
 The candle could be lit and would remain lit for
a while
 Further testing:
 Conclusion
 Priestley discovered that a plant releases a substance
that keeps a candle burning and a mouse living. This
substance, oxygen, is released during photosynthesis.
 Summarize Priestley’s experiment in 3-5
sentences. Be sure to include his conclusions!
 Ingenhousz’s Experiment
 Showed that the effect observed by Priestley
occurred only when the plant was exposed to
light
 Conclusion:
 Light is necessary for plants to produce
oxygen
 Summarize Ingenhousz’s
experiment in 3-5 sentences. Be
sure to include his conclusions!
 Experiments performed by van
Helmont, Priestley, and Ingenhousz led
to work by other scientists who finally
discovered that in the presence of light,
plants transform carbon dioxide and
water into carbohydrates, and they also
release oxygen.
YouReactants
must know this equation!
Products
6 CO2
+
light
6 H2O chlorophyll C6H12O6
Sugar (glucose)
C: 1 1 6
H: 2 12 12
O: 3 8 18
+ 6 O2
C: 6 6
H: 12 12
O: 8 18
6 CO2
Photosynthesis
light
+ 6 H2O chlorophyll C6H12O6
+ 6 O2
Sugar (glucose)
Cellular Respiration
C6H12O6 + 6 O2
Sugar (glucose)
6 CO2 + 6 H2O + energy
 Photosynthesis uses
the energy of
sunlight to convert
water and carbon
dioxide into high
energy sugars and
oxygen.
 Pigments – substance that absorbs
visible light
 Most important for
photosynthesis:
 Chlorophyll a – primary pigment
 Chlorophyll b – collects and
passes energy to chlorophyll a
 Accessory pigments – absorb
other wavelengths of light
 Carotene, xanthophyll,
anthocyanin
1. Without using notes: write the reactants and
products of photosynthesis!
Reactants
_________ + __________
Products
____________ + _________
10 minutes
to finish
and drop!
 The affect of light color on the rate of photosynthesis
 RED
 BLUE
 GREEN
 COLORLESS
 What color showed the highest rate of photosynthesis?
(look at your chlorophyll absorption worksheet)
 Why?
 The affect of light intensity on the rate of
photosynthesis
 1-10
 What light intensity showed the highest rate of
photosynthesis?
 Why?
 The affect of carbon dioxide level on the rate of
photosynthesis
 1-10
 What carbon dioxide level showed the highest rate of
photosynthesis?
 Why?
 Where does photosynthesis take place?
Site of photosynthesis: CHLOROPLASTS
 Chloroplasts contain:
 Thylakoids
Light
 Granum
Dependent

(stacks of thylakoids)
 Stroma
Reactions
Light Independent
Rxns / Calvin Cycle /
Dark Reactions
Draw this in your notes!
What is the purpose of
What layer of cells
the spongy layer, why are
contain the most
there air spaces in
chloroplasts? Why?
between the cells?
A.
B.
C.
D.
E.
F.
G.
H.
Cuticle
Upper Epidermis
Palisade layer
Vein
Spongy layer (air spaces)
Lower Epidermis
Stomata
Guard Cells
guard cells
Stomata open when the internal pressure of the guard cells rises as a
result of water absorption. Since the walls of the guard cells are
relatively flexible at the side of the stoma, the guard cells expand
vertically and the stoma subsequently opens.
Open stoma
guard cells
• Opening formed by two _______________.
underside
• Found on the _______________
of the leaf.
CO2 to enter the leaf.
• Allow _______
O2 and ______________
• Allow _______
water vapor to exit.
water
• Open by filling up with ___________.
• Conserve water by closing __________.
at night
Closed stoma
 Take out your microscope and obtain a lilac leaf cross
section.
 Sketch and LABEL your leaf layers on MEDIUM POWER
ONLY!
Answer:
1. How does water reach the cells of the
leaf?
2. Which layer of cells has the most
chlorophyll? THINK ABOUT IT!
3. Where is the chlorophyll located
inside the cells?
4. How does CO2 get into the leaf?
5. What regulates the stomata's?
6 CO2
+
light
6 H2O chlorophyll C6H12O6
Photosynthesis
occurs in two stages
+ 6 O2
Light Dependent Reactions
I.
Requires light
 Occur in the grana (where chlorophyll is kept)

 4 Major events
1.
2.
3.
4.
H2O is split by energy from sunlight
Oxygen is released
H+ bonds with NADP  NADPH
ADP + P ATP
II. Light Independent Rxns / Dark
Rxns / Calvin Cycle
 DOES
NOT require light
 Occurs in the stroma
 2 Major events
1.
2.
CO2 joins with the H from NADPH
to make glucose (C6H12O6)
ATP  ADP + P
Extra Credit
opportunity DUE
MONDAY:
TEN Points if you write
a Photosynthesis play.
A.
B.
C.
D.
E.
F.
G.
H.
Dark Blue
Pink
Yellow
Orange
Light Blue
Pink
Opening between green
Green